South Australian Cancer Registry data for 1977-1987 show an increase in the recorded incidence of invasive malignant melanomas of the skin of approximately 54% in men and 33% in women. However, the abrupt nature of this increase after a relatively stable incidence level in 1977-1981, the absence of any evidence yet of an increase in mortality after this increase in incidence, and the trend towards thinner lesions are consistent with the conclusion that earlier diagnosis has had an influence. Case-survival rates were higher in 1982-1987 compared with 1977-1981. The thickness of lesions at diagnosis was less for women, younger patients and patients from more affluent areas; parallel trends were found in case-survival rates. After adjusting for tumour thickness and the level of invasion at diagnosis, trends in survival by sociodemographic features were not apparent. The implications of these and related findings for cancer control programmes are discussed.