Data and statistics are presented on cancer death certification in Switzerland in 1990-1994, updating previous publications covering the period 1951- 1989. Data for 1990-1994, grouped into 30 categories, are presented in 10 tables as 5-years age- and sex-specific absolute and percentage frequencies of deaths, and average annual crude, age-specific and age-standardized rates, at all ages and truncated for the 35- 64 year age group. Male-to-female ratios of mortality rates, and ranks of the ten most frequent cancer sites have also been tabulated, and all-ages and truncated age-standardized rates for most cancer sites plotted for 9 calendar quinquennia. Total cancer mortality rates decreased in both sexes (from 268.7 in 1985-1989 to 251.8/100,000 males in 1990-1994, and from 201.5 to 190.6/100,000 females; age-standardized rates on the 1980 Swiss population), particularly at younger ages and in males. Decreases in rates were observed in males for lung (from 68.7 to 62.7/100,000), oesophagus, larynx and prostate (at younger middle age), in females, for breast and genital sites and, in both sexes, for stomach, colorectum, gall-bladder pancreas, skin, bladder; kidney brain and most lymphohaemopoietic neoplasms. Increases were observed for pleura in males, and for larynx and lung (from 11.9 to 14.8/100,000) in females. Thus, with the major exception of lung cancers and a few other tobacco-related neoplasms in females, cancer mortality rates in Switzerland over the period 1990-1994 were generally favourable.