Data on over 3,700 patients with renal cell carcinoma, reported to the Connecticut Tumor Registry from 1935 through 1973, were used to assess incidence, survival, and associations of risk with demographic characteristics. Incidence increased over time among men, but not among women; a birth cohort effect suggesting increasing incidence rate over time was demonstrated for men. A comparison of male and female agespecific incidence rates indicated that, in the 15- to 39-year-old age group, men were three times more likely than women to develop the disease; after age 40, renal cell carcinoma was diagnosed in men twice as often as in women. Survival probability has increased from 1940 to the present time. A high density of persons per square mile was associated with a higher-than-expected incidence. No trends in incidence according to socioeconomic status were observed.