We examined all babies born live (4346) at two Finnish hospitals in the course of one year to determine the frequency of birthmarks, specially pigmented lesions, among Finnish newborns. All birthmarks excluding common salmon patches on the forehead and neck were recorded and photographed at birth. The babies were re-examined at the age of three months. Various birthmarks were recorded for 241 of 4346 babies, i.e. for 5.5% of all newborns. Ninety-one (2.1%) infants had congenital pigmented skin lesions, 167 (3.8%) had various vascular lesions and 21 (0.5%) had other birthmarks. The frequency of congenital melanocytic naevi was 1.5%. Most of the naevi were less than 20 mm in diameter. Only one child had a giant naevus. The frequency of congenital naevi in our study was the same or somewhat higher than previously described (1-8) but fewer other pigmented skin lesions were found than in previous studies perhaps due to racial differences.