This cross-sectional study was carried out to investigate the frequency of consanguineous marriage in a group of army conscripts in Ankara and the factors affecting this. Of 4153 soldiers, 387 were married. The rate of marriage between first cousins was found to be 19·1%, and the overall rate of consanguineous marriage was 24·1%. Consanguineous marriage was found to be significantly prevalent among soldiers who were born in and still living in the Eastern region; among those who lived in villages; among those whose parents as well as themselves had low educational levels; and among those whose marriages were arranged by their families. Neither the payment of bride-price nor the presence of consanguinity between parents was a significant factor for consanguineous marriage. In addition, the age of the soldier and the age at marriage were significantly lower among soldiers married to first cousins than among soldiers whose marriages were not consanguineous.