Abstract: The distribution of ABO blood group was investigated among onchocerciasis patients in Agbokim, a rural community within the Cross River basin Nigeria. A total of 398 individuals comprising 224 clinically and parasitologically confirmed onchocerciasis patients and 174 apparently healthy age-matched individuals (control) were used for this study. Frequencies of the blood groups were 62.06% for blood group O, A (17.84%); B (16.58%) and AB (3. 52%). The gene frequencies were, O (0.621), A (0.178), B (0.166) and AB (0.035), while the allelic frequencies were P = 0.11, q = 0.10 and r = 0.79. There was a significant (p< 0.05) association between ABO blood group system and onchocerciasis infection with blood group O subjects being more susceptible to infection than the other blood groups. The possible exploitation of this association in the production of candidate vaccine and/or potent drug against the adult worm is discussed.