The subject of this paper is non-contractual liability of physicians in Roman law. Contrary to the common perception of Roman society, where “only a physician can commit homicide with complete impunity” (Plinius, Nat. Hist. 29,8), parallel to the development of medicine, rudimentary stages of a physician's liability for damage through negligence also evolved. Through the interpretation of available legal sources, focusing particularly on situations concerning slaves and free persons as patients, the forms of legal protection of patients are primarily determined. Special attention in the central part of the paper is devoted to the problem of causality and the development of fault-based liability. The last part of the paper examines the forms of compensation for damage, based on which conclusions are finally drawn about the extent of the development of medical liability ex delicto.