A one year (2009-10) prevalence study on gastrointestinal parasitism was conducted in crossbred and local cattle, Chittagong, Bangladesh. Fecal samples were collected randomly from 216 crossbred and 432 local cattle of four representative areas in three consecutive seasons. Samples were examined by routine coproscopical methods. The effects of topography, season, age and gender were tested in both crossbred and local cattle. The overall prevalence of gastrointestinal parasitic infections was 39.75% and 46.25% in crossbred and local cattle, respectively. Frequency of trematodes and nematodes infections was persistent in all the study areas. The highest prevalence of trematodes infections was found in Boalkhali (32.41%) compared to Noakhali (23.14%), Rangunia (18.53%) and Khagrachori sadar Upazila (17.60%). Prevalence of nematodes infection was the highest (25.93%) in Noakhali sadar Upazila in local cattle. Occurrence of gastrointestinal parasitic infections was more common in rainy season followed by summer and winter. Significantly higher prevalence of Paramphistomum spp (20.13%) was found in rainy season whereas Haemonchus spp (5.56%) and Moniezia spp (4.16%) were higher in summer (P<0.05). Paramphistomum spp infections were more frequent in adult while Toxocara spp were predominant in calf (P<0.05). Prevalence of Haemonchus spp (4.86%) infections was significantly higher in local adult cattle whereas Trichostrongylus spp (4.86%) infections were predominant in local young cattle (P<0.05). It could be stated that season, age were the important predictor of gastrointestinal parasitism. We recommended further studies for molecular detection of such diseases which will assist to take necessary preventive measures. 1330976338.php