The purpose of the present study was to describe the cancer pattern in a cohort of farmers in Iceland and to compare their cancer incidence to that of other Icelandic males. This is a retrospective cohort study. The study population was obtained from a register at the Farmers' Pension Fund and comprised 5922 men. Viewed as a whole the cohort shows a significant lower incidence for all tumours than expected. The same is true of SIR for cancer of colon, lung, prostate, bladder and other urinary organs with SIR of 47, 41, 71 and 51, respectively. However, some etiologic factors may contribute to the increased risk of some cancer sites among farmers. There was an excess for Hodgkin's disease SIR 251, and for cancer of lips, skin (excl. melanomas), nervous system, non-Hodgkin's lymphoma and leukemia with SIR of 183, 150, 128, 142 and 151, respectively, however not statistically significant. The authors suggest that something in farmers lifestyle protects them from various kinds of cancer.