Trends in cancer mortality in Switzerland were analysed over the period 1980-2001, on the basis of the World Health Organization database. Appropriately developed correction factors were utilized for the period before 1995, to allow for spurious trends introduced by the change between the 8th and the 10th revisions of the ICD. Steady declines in cancer mortality were observed, particularly from the mid-1980s onwards. Over the last decade, the fall in overall age-standardized (world standard) cancer mortality was 11.1% in men (from 158.1 in 1990-1991 to 140.6/100 000 in 2000-2001) and 7.6% in women (from 91.6 to 84.7/100 000), and the decline was larger in truncated rates from 35 to 64 years (-18.0 and -9.7%). In men, all major tobacco and alcohol neoplasms have declined until the late 1990s but have levelled off over the last few years, reflecting recent trends in alcohol and tobacco consumption. The fall in male lung cancer mortality was 20% over the last decade (from 42.9 to 34.3/100 000). In contrast, lung cancer mortality in women has steadily increased by 38% between 1981 and 1991 and by 47% between 1991 and 2001, to reach 10.7/100 000 at all ages and 18.3 at age 35 to 64, due to increased prevalence of smoking in subsequent generations of Swiss women. Other sites showing substantial declines include stomach and colorectum in both sexes, (cervix) uteri and breast in women. Likewise, prostate cancer showed modest favourable trends after 1995. Steady declines were observed for leukaemias, Hodgkin's disease and testicular cancer, namely, the neoplasms most influenced by therapeutic improvements, while trends in lymphomas and myeloma showed no clear pattern. [Authors]