Medical Malpractice in Spain: Criminal Liability and Defense (2026)

Few accusations are as distressing for a practitioner as a complaint for malpractice. It is essential to start from one core idea: a poor clinical outcome is not, in itself, a crime. Medicine works with risks, complications and margins of uncertainty, and criminal law only intervenes where criminally relevant negligence concurs. As criminal defense lawyers in malpractice cases, we explain which offenses are at stake, what penalties they carry and how the healthcare practitioner's defense is built.

When Malpractice Is a Crime

The Criminal Code (CP) contains no standalone offense of "medical negligence". A practitioner's criminal liability is channeled through the result-based reckless offenses: reckless homicide (Art. 142 CP) where the patient's death is caused, and reckless injury (Art. 152 CP) where harm to health or bodily integrity is caused.

The core element, in both cases, is negligence: the breach of an objective duty of care that must, in addition, be the cause of the harmful result. It is not enough for the patient to suffer harm; it must be established that this harm is the consequence of careless conduct by the practitioner, and not of the natural course of the illness, an unavoidable complication or a typical risk previously assumed.

Reckless Homicide (Art. 142 CP)

Where negligent medical conduct causes the patient's death, Art. 142 CP comes into play, distinguishing two levels of gravity:

• Gross negligence (Art. 142.1 CP): one to four years' imprisonment. If the homicide is committed through professional negligence, special disqualification from practicing the profession, trade or office for a period of three to six years is also imposed.
• Less-serious negligence (Art. 142.2 CP): a fine of three to eighteen months. This offense can only be prosecuted upon complaint by the injured party or their legal representative.

Professional negligence is that which stems from an inexcusable ignorance or breach of the rules proper to the profession, and entails the additional disqualification. It is distinguished from the practitioner's ordinary negligence, a lapse that anyone could commit regardless of their technical skill. This distinction is not theoretical: professional disqualification can affect a practitioner's career as severely as the prison sentence itself.

Reckless Injury (Art. 152 CP)

If the malpractice causes injury rather than death, Art. 152 CP applies, its penalty graded according to the risk created and the result produced:

Form	Penalties
Gross negligence, injuries under Art. 147.1	Three to six months in prison or a fine of six to eighteen months.
Gross negligence, injuries under Art. 149 (loss or uselessness of a principal organ or limb, sterility, serious deformity…)	One to three years' imprisonment.
Gross negligence, injuries under Art. 150 (loss or uselessness of a non-principal organ, deformity)	Six months to two years' imprisonment.
Less-serious negligence (Art. 152.2)	A fine of one to two months (injuries under 147.1) or three to twelve months (injuries under Arts. 149 and 150).

As with homicide, where the injuries are caused through professional negligence, Art. 152.1 CP also imposes special disqualification from practicing the profession, trade or office for a period of six months to four years. The offense of injury through less-serious negligence can only be prosecuted upon complaint by the injured party.

The Lex Artis Ad Hoc: the Decisive Criterion

The centerpiece of any malpractice accusation or defense is the lex artis ad hoc. It is the body of technical rules that medical science deems correct, but applied to the specific circumstances of the case: the patient's clinical condition, the material and human means available, the urgency of the situation and the setting in which the practitioner acts (a scheduled operating theatre is not the same as a night-time emergency with limited resources).

If the practitioner acted in accordance with the lex artis ad hoc, there is no criminal negligence, even where the outcome was unfavorable or even fatal. Medicine is an obligation of means, not of result: the physician's duty is to place at the patient's disposal the knowledge and diligence that can be required, not to guarantee a cure. Establishing that the lex artis was observed, through expert evidence, is the principal line of defense.

Excusable Error versus Negligence

Not every medical error is negligence. The settled case law of the Supreme Court distinguishes the excusable error of judgment —that made by a diligent professional faced with a complex, doubtful or atypical clinical picture— from criminally reproachable negligence, which involves the breach of an elementary duty of care. A mistaken diagnosis reached after a reasonable assessment and in line with the state of science is, frequently, an excusable error rather than a crime.

The defense works precisely on this distinction: to show that the clinical decision was reasonable in light of the information available at that moment, free from the bias of later knowledge of the outcome (so-called hindsight bias), which tends to present as obvious what was not obvious when the practitioner had to decide.

Causal Link and Objective Imputation

For an offense to exist, negligent conduct alone is not enough: it must be the cause of the harmful result. The defense examines in detail whether the harm truly derives from the practitioner's conduct or from extraneous factors: the underlying illness itself, the patient's prior conditions, their failure to follow treatment or unforeseeable complications.

Here objective imputation operates: even where there is a lapse, the result is only attributable to the practitioner if it materializes the risk that their conduct created. If the outcome would have occurred anyway with correct conduct, or if it responds to an independent hypothetical causal course, criminal liability falls away. The complete clinical history is, on this point, the decisive documentary evidence.

Informed Consent

Informed consent documents that the patient knew of and accepted the typical risks of the procedure. It does not render lawful a negligent course of conduct, but it serves two important defensive functions: it separates the risk assumed by the patient from harm attributable to malpractice, and it allows claims based on an alleged lack of information to be rebutted. Its proper collection, with an explanation of alternatives and risks, and its record in the clinical history are first-order elements in the practitioner's defense.

Criminal Route versus Civil Claim

It is essential to distinguish two planes that are often confused:

• Criminal liability: requires negligence and a result of death or injury. It entails a penalty (imprisonment or fine) and, where applicable, disqualification. It is found only in cases of a certain gravity.
• Civil or administrative liability: seeks compensation for the harm and is governed by different criteria. It does not require gross negligence and may be found even where no crime exists; it is directed against the practitioner, the center or the insurer.

Many malpractice claims are resolved entirely through the civil route —against the public health service, through the administrative route of patrimonial liability— with no criminal reproach whatsoever. A legitimate aim of the defense is, where appropriate, to steer the dispute toward that arena, avoiding a criminal conviction that brings with it a criminal record and disqualification.

Defense Strategy for the Healthcare Practitioner

The defense against a malpractice complaint is built on several pillars:

• Medical expert evidence: a report by an expert in the relevant specialty assessing whether the lex artis ad hoc was observed. It is the key piece of evidence in the proceedings.
• Analysis of the clinical history: a complete chronological reconstruction of the care provided, to establish what was known and what was decided at each moment.
• Coordination with the professional liability insurer, aligning the criminal strategy with any compensation response.
• Procedural guarantees: the right not to testify without legal assistance, scrutiny of the prosecution's expert evidence and of the chain of custody of the clinical records.

Each case calls for its own assessment. The firm analyzes the viability of the complaint and advises on the most suitable strategy —a frontal defense or, where the facts so advise, a negotiated resolution in the civil sphere— always with discretion and without anticipating outcomes.