The paper discusses the modern aspects of diagnosis and expertise of pilots suffering from gall-stones. The present-day methods were used to examine 196 pilots of different aviation categories (helicopter in the main). Semiotic signs of different variations of gall-stones are studied, comparative characteristics of diagnostic methods are demonstrated, more effective algorithms of examination are elaborated. It is shown that in the radio-clinical examination the ultrasonic investigation holds the lead in the diagnostic algorithm enabling in the shortest way early and correct detection of concretions in the biliary tracts. Viscous putty-like bile in the gall bladder found during preventive monitoring is an unfavourable sign calling for correction of diet, motor activity and medicamentous therapy.