Trends in age-specific and age-standardized mortality from 10 major cancer sites and total cancer mortality in the USSR were analyzed for the period 1965-1990, on the basis of the World Health Organization mortality database. Gastric cancer mortality declined substantially. Still, these rates were among the highest registered in the world, and in I990 stomach cancer accounted for over 85,000 deaths, being the second cause of cancer death (and the first one until 1980); further, there was some indication of a levelling of the declines in gastric-cancer rates for both sexes over most recent calendar years. Likewise, uterine-cancer mortality declined between 1965 and 1985, but there was no further decline over the last 5 years. Upward trends were registered for cancers of the intestine, of the breast and of the prostate. Mortality from these neoplasms, however, was still comparatively low by worldwide standards. Leukaemia rates were stable in both sexes. Substantial rises were observed for cancers of the oral cavity and pharynx, larynx and, chiefly, lung. Even more unfavourable was lung-cancer mortality in young and middle-aged males, since the truncated rate of 121/100,OOO in 1990 was higher than the values reached by countries like England and Wales or Finland even at the top of their epidemic in the 1960s. and trends in the USSR were still upwards. Thus, total cancer mortality was I76/ I00,000 males in 1965, declined to I70 in 1970, but increased thereafter, particularly over the last decade, to reach 203/ I 00,000, i .e., one of the highest rates on a worldwide scale. Among females, the overall cancer mortality rate declined between I965 and 1975. but rose thereafter to a value intermediate on a worldwide scale. These recent unfavourable trends of cancer mortality in the USSR indicate that, in the absence of adequate intervention, particularly on the tobacco-related cancer epidemic, overall cancer mortality will continue to rise in the foreseeable future.