This study was conducted to determine the prevalence of gastrointestinal helminth parasites in Clarias gariepinus with the view of quantifying its helminthic burden in Abuja. The study was carried out in three area Councils of Abuja, Nigeria, between the months of April and August 2015. A total of 83 live fishes (Clarias gariepinus) which includes 28 males and 55 females were randomly purchased from local fishermen and were subjected to examination for gastrointestinal helminth parasites. The lengths and weights of the fishes were measured prior to dissection and the parasites recovered were identified. Results indicated that 56 of the examined fishes were infected with various species of helminth parasites, giving a prevalence of 67.5%. Parasites were identified as Procamallanus laevionchus (32.5%), Rhabdochona congolensis (18.1%), Polyonchobothrium clariae (10.8%), Allocraedium species. (3.6%) and Heterophyid flukes (2.4%). The highest prevalence was recorded for nematodes (50.6%) followed by cestodes (10.8%) and trematodes (6.0%). Worthy of note, was the recovery of Heterophid flukes in this study which have not been previously reported in Nigeria and pose a great zoonotic threat. It was observed that fishes of standard length range of 20-30cm (82.4%) were more infected than those of 30-40cm (65.0%) and 40-50cm (61.5%). The highest prevalence of infection (78.6%) was recorded in fishes with body weight of 500-600g while the lowest (58.8%) was recorded in fishes with body weight of 600-700g. The males had higher percentage prevalence (67.9%) than the females (67.3%). The result of the study indicated that the association (P˂0.05) between the prevalence of infection, sex, length and weight of the host was not statistically significant (χ 2 = 0.00289, 2.24 and 1.55; degree of freedom= 1, 2 and 5 respectively). The helminths recovered were found to parasitize the stomach and intestinal lumen, the latter being more affected.