The results of studies concerning the mortality rates of both sexes are of great similarity in all industrial countries. For underdeveloped countries, little information is available, but analogue proportions can be supposed. In the nations of the industrialized world males have a significantly higher mortality rate, which shortens their life expectancy in comparison with that of woman. Since about 1970 a deceleration of this development has been observed. The diseases responsible for this fact are ischemic heart disease, lung cancer, accidents, and other traumatic incidences, but also infectious diseases. Concerning the origins of ischemic heart disease, the influence of sex hormones especially on the lipid profile are being discussed; nevertheless, for the enhanced coronary risk of males environmental and behavioral factors seem to be more important than biological reasons. As for carcinosis being a reason for the mortality of males, lung cancer is in the foremost position. Cigarette consumption, as well as the higher exposure to cancerogenic substances related to typically male professions, are held responsible for this. As for other types of cancer, environmental factors depending on gender are strongly considered as a reason for different rates of mortality. Furthermore, sociological explanations for these differing frequencies are being discussed. Occupational differences and the different positions held in working life by each gender are believed to be responsible for the higher rate of mortality among males. Also, risktaking behavior seems to be found more often among males, than among females. A variety of hypotheses based on genetics have been given to explain the different gender-specific rates of mortality, but none of them has yet been proven correct.(ABSTRACT TRUNCATED AT 250 WORDS)