The article presents the issue of the superior’s liability for injury caused by subordinates during treatment. The issues raised are analysed primarily through the prism of the case law, using also historical analysis. The practice of judicial application of law in Poland has led to the formation of a line of case law which adopts Article 430 of the Civil Code as the basis for the liability of medical facilities for injury caused by medical doctors. Problems regarding the hospital’s responsibility for a doctor’s activities during diagnosis and treatment date back to the time of the Code of Obligations and the concept of shared liability, which was adopted then. Modern jurisprudence sanctions the position of a medical doctor as a subordinate of a medical facility, despite the doctor’s independence in the practice of the profession. A medical doctor always acts as a subordinate of a medical facility when he/she performs activities “for” or “on behalf of” the medical facility. This practice of applying the law should be considered beneficial for the aggrieved persons who sue the medical facility for compensation, because they are able to obtain it more easily and do not need to demonstrate who among the medical staff has caused their injury.