A case-control study of cutaneous malignant melanoma (CMM) was based on 523 incident cases and 505 age- and sex-matched controls selected from the general population. The purpose was to investigate the relative risk of developing CMM associated with different sun habits and indicators of pigmentation, such as skin type, eye colour and hair colour. Compared to people with black hair, blonde subjects had a relative risk of 74.4 (95% confidence interval, 45.8-120.8). Associations with skin type and eye colour were considerably weaker. Relative risks of about 1.5-2.5 were found for certain sun habits. The results suggest that in a population of Caucasian origin with a predominantly fair complexion, pigmentary status characterized by hair colour is a far more important aetiological factor than sun habits.