Epidemiology of gastro-intestinal parasites of water buffaloes was investigated in Kurigram district of Bangladesh between November 2007 and October 2008 through coprological examination. A total of 236 water buffaloes were examined, among them 144 (61.02%) buffaloes were found infected with one or more species of gastro-intestinal parasites. Nine species of gastro-intestinal parasites were identified, of them four species were trematodes, namely, Paramphistomum cervi (29.24%), Fasciola gigantica (22.46%), Schistosoma indicum (1.27%), Schistosoma spindale (0.85%); three species were nematodes, namely, Toxocara vitulorum (2.54%), Strongyles (0.85%), Strongyloides sp. (0.42%) and two species were protozoa, namely, Eimeria sp. (3.39%) and Balantidium coli (37.29%). No cestode was detected. Among the gastro-intestinal parasites mixed infection was common. In this investigation, prevalence of parasites in relation to age, sex and seasonal dynamics was also studied. Significantly (p<0.01) higher prevalence of gastro-intestinal parasites was observed in rainy season followed by summer and winter seasons. Males and females were almost equally (odd ratio 1.08) susceptible to gastro-intestinal parasitic infection. In the age groups, young (< 2 to 5 years) were mostly (p<0.01) susceptible to gastro-intestinal parasites. In the present study, EPG (Egg/cyst Per Gram of Feces) was also determined. The range of EPG varied from 100-5000 among the identified parasites. The results of the present investigation revealed that the prevalence of gastro-intestinal parasites in buffaloes is very common and quite severe. It is imperative that integrated strategies and measures be taken to control gastrointestinal parasitic infections in buffaloes in kurigram district and elsewhere in Bangladesh.