This study shows that, unlike most diseases, some cancer forms are more common in upper social classes. All cancer cases diagnosed in Finland in 1971-75 aged 30-69 and recorded in the Finnish Cancer Registry (n = 36,500) were linked to the file of the 1970 Population Census of Finland with data on socio-economic status and education. Cancers related to both high socio-economic status and high level of education in men were colon, prostate, testis, kidney and melanoma of the skin, and in women colon, breast, and corpus uteri. Since 1953, the incidence of all these cancers had been rising, although that of the testicular cancer had levelled off in the seventies.