Basal cell carcinoma (BCC) is the most common malignant tumour of the skin in Caucasians. It often appears on the eyelids but there are no population-based studies on the incidence of BCC of the eyelid in Nordic countries. The mean annual incidence rates of BCC of the eyelid in the region of South-Western Finland from 1977 to 1997 were calculated. The mean annual incidence (per 100,000 population) of BCC of the eyelid showed a statistically significant increase from 0.82 (in 1977-1979) to 2.88 (in 1995-1997). The incidence of BCC of the eyelid was 0.8 in the age group of 30-49 years and rose significantly with age (P < 0.0005) to the maximum of 17.2 in the age group of 80-89 years. There were no statistically significant differences in the incidence rates of BCC of eyelid between males and females or between urban, semi-urban and rural populations. In South-Western Finland the incidence of BCC of the eyelids more than tripled during the years from 1977 to 1997. This may be due to the increase of the elderly population, because the incidence showed a significant increase with age.