Because of the absence of original data concerning the Rh blood group system in Turkey, for the benefit of researchers interested in the human blood groups field, serological results obtained in Hacettepe University Hospitals' Blood Center between 1980 and 1996 have been evaluated for the first time in this paper. During the study, 581,606 people were evaluated for Rho (D) positivity and negativity. In addition, 5,600 people from different parts of Turkey were screened for the five major antigens (D, C, E, c, e) of the Rh blood group system and, according to the results, various gene frequencies and most likely genotypes were calculated. Results clearly show that the Rh blood group system in Turkey is completely, in line with that of the Caucasians.