We considered, by means of a multivariate approach, trends in survival from cutaneous malignant melanoma in relation to patient and tumor characteristics, using data from the Cancer Registry of the Swiss Canton of Vaud. Between 1980 and 1994, 1,229 cases of incident cutaneous malignant melanoma were registered. There was a decline in the proportion of neoplasms in the head and neck and lower limbs, and a rise in those of the trunk and upper limbs, an increase in superficial spreading melanoma and in tumors of limited thickness, mostly in females. Five-year crude survival was 0.68 for males and 0.82 for females, and relative survival of 0.79 for males and 0.89 for females, corresponding to a multivariate hazard ratio (HR) of 0.63 for females vs. males. Survival was inversely related to age, with 5-year relative survival of 0.92 at age 15-44 years, 0.85 at age 45-64 years, and 0.79 at age > or = 65 years. With reference to histological type, no significant difference was observed in males, but in females nodular melanoma showed reduced survival. Compared with melanoma of the limbs, the HR was 1.46 for melanoma of the trunk, and 1.23 for those in the head and neck, and the difference was greater in females. A strong relation, in both sexes, was observed between survival and tumor thickness, with an HR of 3.96 for tumors > or = 4 mm vs. those < 1.50 mm. After allowance for all other factors considered, most recent calendar period of diagnosis was associated with improved survival in both sexes (HR = 0.72), but mostly in females. Although differences in survival tended to be larger during the first 2 years after diagnosis, the pattern was similar for most prognostic factors considered up to 10 years after diagnosis.