Information from a case-control study of all patients with cutaneous malignant melanoma first diagnosed in Scotland in 1987 has been used to derive a personal risk-factor chart that can be used by both the medical profession and the general public. The relative risk of cutaneous melanoma is estimated from the four strongest risk factors identified by conditional logistic regression. These factors are total number of benign pigmented naevi above 2 mm diameter; freckling tendency; number of clinically atypical naevi (over 5 mm diameter and having an irregular edge, irregular pigmentation, or inflammation); and a history of severe sunburn at any time in life. Use of this risk-factor chart should enable preventive advice for and surveillance of those at greatest risk.