We report the cross-sectional age-related prevalence of cutaneous features of the tuberous sclerosis complex in a defined population. Of 131 affected individuals, 126 (96%) exhibited skin signs. Although there is considerable variation in the age of expression of all the skin lesions, there is a trend towards the earlier expression of hypomelanic macules and forehead fibrous plaques compared with facial angiofibromas and ungual fibromas. Shagreen patches are usually present by puberty. Ungual fibromas appeared for the first time as late as the fifth decade and were the only clinical feature in three individuals. Gum fibromas were present in 36%. Ten individuals (8%) presented because of the skin manifestations and 21% received treatment for symptomatic skin lesions. Two individuals had large hamartomas at unusual sites (occiput and forearm).