The present study was conducted with the objective to see the effect of season on oxidative stress parameters in cyclic Murrah buffalo. Forty fi ve cyclic Murrah buffaloes were synchronized for estrus with standard Doublesynch protocol and inseminated fi xed time at 8 and 24hr of last GnRH injection in summer (n = 20) and winter season (n = 25). Blood samples were analyzed for the level of oxidative stress parameters. The overall MDA concentrations were higher (P<0.05) during summer compared to winter season. Furthermore, values were higher (P<0.05) on day of AI compared to days of start of protocol in both seasons. Glutathione peroxidase (GSH-Px) level were similar (P>0.05) between summer and winter season among days of protocol except on day 9, in which GSH-Px level was lower (P<0.05) in summer as compared to winter season (16.9 ± 1.8 vs 24.2 ± 2.0 U/ml of hemolysate). The Superoxide dismutase (SOD) concentrations were higher (P<0.05) in winter as compared to summer at the time of start of protocol however; on day 9, the values were lower (P<0.05) for winter than summer. In conclusion, MDA is more reliable parameter to measure oxidative stress in Murrah buffalo and it increase during summer season and hence reduce the conception rate.