Background and Design: Becker nevus (BN), characterized by sharply and irregularly bordered, unilaterally localized, hyperpigmented macules and patches which can go along with hypertrichosis, is a kind of hamartomatous lesion that predominantly affects males 4-6 times more frequently than females. It is usually seen in peripubertal period. There are scarce epidemiological data on BN and the prevalence in our country is also unknown. In this prospective, cross-sectional study, we aimed to determine the prevalence of BN among young adult males in Turkey.Materials and Methods: 8207 male candidates from different regions of Turkey who would be selected as a student in a governmental school and were referred to the dermatology outpatient clinic between March 2012 and August 2012, were included in our study. In addition to comprehensive medical examination, candidates were also inspected for the presence of BN, its localization, the asociation with hypertrichosis, and the findings were recorded.Results: The mean age of the candidates was 20.02±1.40 (range: 18-22) years and the mean age at BN onset was 12.2. BN was detected in 68 out of 8207 candidates (two different localizations in one subject). The prevalence of BN was calculated as 0.82%. The distribution of BN localization was as follows: mostly on the pectoral region ( 24.64%), and in decreasing order, on the scapular region (23.18%), shoulder (18.84%), infrascapular region (17.39%), arm (5.80%), abdomen (5.80%) and the thigh (4.35%). Hypertrichosis was present on 34 out of 69 BN (49.2%) that were found in 68 subjects.Conclusion: In our study, it was determined that BN was mainly localized on the pectoral and scapular regions, the prevalence was 0.82% and, 49,2% of the lesions were hypertrichotic
