Medical malpractice is an act or omission by a health care provider which deviates from accepted standards of practice in the medical community and which causes injury to the patient. Simply put, medical malpractice is professional negligence (by a healthcare provider) that causes an injury.

In the United States and other countries, a specific medical malpractice law has developed. In English law, the issue of liability is a subset of professional negligence where, under the Bolam Test, a doctor will be liable unless shown to have acted in accordance with a reasonable body of medical opinion.