BACKGROUND: Analysis of trends in cancer survival in defined well surveilled populations can provide useful indications on advancements in cancer management and treatment. PATIENTS AND METHODS: Survival rates from the Vaud Cancer Registry were computed for 31,158 cases registered in 1984-1993, and compared with those registered in 1974-1978 and 1979-1983. RESULTS: A systematic, albeit generally moderate, tendency towards increasing five-year relative survival was observed for both sexes and most major cancer sites, including oral cavity and pharynx (0.38-0.43). stomach (0.21-0.26), colon (0.49-0.55), rectum (0.45-0.51), lung (0.08-0.12), skin melanoma (0.67-0.89), female breast (0.67-0.80), endometrium (0.72-0.84), ovary (0.28-0.37). prostate (0.44-0.66), testis (0.73-0.96), bladder (0.31-0.50), kidney and renal pelvis (0.41-0.59), thyroid (0.73-0.81), non-Hodgkin's lymphomas (0.37-0.63), Hodgkin's disease (0.61-0.81), and leukaemias (0.27-0.39). Survival for all cancers and both sexes combined, rose from 0.51 0.64 (0.57 for males, 0.71- for females). No appreciable change in survival was observed for cancers of oesophagus, liver, gallbladder, pancreas, larynx, cervix uteri, brain, multiple myeloma, as well as unidentified or unknown origin neoplasms. CONCLUSIONS: Survival estimates for most cancer sites are comparable to the US SEER dataset, and their pattern of trends are discussed in terms of improved diagnosis and treatment for various neoplasms.