Blood group alleles and their frequencies were estimated within a Denizli fowl flock. Sixteen full sib family groups we-re formed to facilitate the identification of segregating alleles. Immune antisera were produced by means of reciprocal immunizati-ons between the parents. Reference reagents were obtained from WE Briles, Department of Biological Sciences, Northern Illino-is University. Reference reagents were used for the blood typing. In the flock in question, the allele genes which belong to blood group systems A, B, C, D, E and L were estimated and their frequencies calculated. In the A blood group system, A1, A 2, A 3, A 5, A 7 and A 12 alleles were estimated and their frequencies were calculated as 0.07, 0.11, 0.39, 0.11, 0.01, and 0.31 respectively. Alleles of B 2, B 6, B 14, B 19, B 21, B 25 were estimated in the B blood group system, frequ-encies were calculated as 0.09, 0.37, 0.19, 0.11, 0.21 and 0.03 respectively. Frequencies of C 1, C 2, and C 5 alleles that were es-timated in the C blood group system were calculated as 0.32, 0.14, and 0.55 respectively. For D 1, D 2, D 4, D 6, D 6 and D 7 alleles in the the D blood group system, frequencies were calculated as 0.02, 0.09, 0.54, 0.07, 0.23 and 0.05 respectively. The frequency of L^ 1 allele the L in blood group system was calculated as 1.00 while frequencies of E^ 2, E^ 3 and E^ 5 alleles in the E blood group system were calculated as 0.40, 0.54 and 0.06 respectively. In this study, in the D blood group system, a new allele D 7 was revealed apart from those 6 alleles which had been designated pre-viously.