The main purposes of the health surveillance of workers exposed to anaesthetic gases are: a) the finding of disorders either reliable to the exposure or incompatible with the activity in the operating theatre; b) the epidemiological evaluation of the late effects. Simple and rigorous methods to estimate the previous and the current risk are suggested. The main data to be collected during the medical examination are indicated. The registration of the data of the reproductive function by a protocol of recording is proposed. For the health surveillance of workers in Health Care Institution it's advisable to establish an interdisciplinary group, referring to a specialist on occupational medicine.