A cross sectional study was conducted from November, 2013 to August, 2014 in lake Hayq to identify the most common genera infectingfish and determine the prevalence of parasites. A total of 1200 randomly selected fish species comprising of 400 African catfish (Claries gariepinus), 400 common carp (Cyprinus carpio) and 400 Nile tilapia (Oreochromis niloticus) were sampled. The fish ware collected from two different sites (Southern and Western part) of the Lake. All the sampled fish were carefully examined in laboratory to investigate the external and internal parasites. Chi- square test was used to analyses the data. The overall prevalence of the parasites in Lake Hayq fishes was 59.4% prevalence of parasites was higher in C. gariepinus (n= 382 infected, 95.5%) followed by 0. niloticus (n=291, 72.8%), and C. carpio (n= 40, 10%). In all fishes examined the most frequently found parasitic genera was Contraceacum (58. 6%), followed by Clinostomum (20.4%), Camallanus (10.7%), Eustro ngylo ides (4.1%) Euclinostomum (2.5%), Trichodina (0.9%), Proteocephalus (0.94%), Dolops (0.64), Ligula intestinalis (0.6%) and Argulus (0.5). The distribution of parasite genera was significantly affected by sex and species offish (p<0.05). The prevalence was higher infemales (55.4%) than males (44.6%). From the whole organs examined, pericardium was highly infested by seven types of different parasites followed by abdominal cavity and mesentery which were highly infested with Nematodes. Fishers and other people who have developed the habit of consuming raw fish would be at higher risk of becoming infected by zoonotic parasites. Therefore awareness creation activities and control of fish parasites should be conducted in the study lake. Keyword: Commercial Fishes, fish parasites, Lake Hayq, Prevalence, Intensity