The subject matter of this publication is the legal assessment of endogenous infection – the specific type of hospital infections. The main aim of the publication is to answer the question of whether medical and legal grounds exist for civil liability for endogenous infections and for treating those infections as cases of medical malpractice or medical events. The research method adopted is a case study. The authors have analysed a civil lawsuit for compensation instituted by an infected patient against a Polish hospital, adjudicated in 2013. The main conclusion of the publication is to postulate distinguishing medical malpractice from complications resulting from the reactions of the human body to treatment. The authors argue that endogenous infections should be treated as the latter-mentioned of these two cases.