The results of studies on several aspects of poisoning caused by lead. mercury, manganese, hard metal, nickel, and uranium are reviewed. Studies on lead comprise the development of methods for the determination of lead in biological material, the analysis of pathophysiological processes and clinical manifestations of saturnism, and the elaboration of criteria for the assessment of working capacity in intoxicated workers. Investigations concerning mercury poisoning include the determination of methods for the determination of mercury in biological material, observations on the pathophysiological and clinical manifestations of mercurialism, and the drawing up of criteria for the assessment of fitness for work in intoxicated workers. In connection with the occurrence of manganism in the production of manganese alloys in Šibenik, studies were conducted on the clinical picture of manganism, technological processes in which the workers were exposed to manganese smoke and dust, and the measures to be undertaken to prevent manganism. Results are presented of the follow up of a group of workers exposed to hard metal dust and the pathogenesis of pneumoconiosis caused by hard metal. Work is reviewed on nickel allergy observed in galvanizers in various industrial establishments. The review also includes results of observations on the harmful effect of uranium; in this connection polarographic methods have been developed for the determination of small amounts of this metal in the blood, urine and kidneys.