Data about the incidence of skin cancer in the Islamic Republic of Iran are lacking. This study investigated trends in the incidence of skin cancer (ICD-10 category C44, other malignant neoplasms of skin) in 6 regions using data from the Iranian cancer registry from 2000 to 2005. The standardized incidence rates in each year were calculated by the direct method using the standard World Health Organization population and a Poisson regression model was applied to analyse trends. Over the study period, 30 701 cases of cancer were identified, rising from 2353 in 2000 to 8484 in 2005. The male-to-female ratio was 1.6. The age-standardized incidence rose significantly from 3.8 cases per 100 000 in 2000 to 13.0 in 2005 (slope = 0.26), and the same trend was seen in all regions except the region to the east of the Caspian Sea. This increasing incidence of skin cancer in the Islamic Republic of Iran is similar to that reported in other countries.