Background: The   beneficial  effect of  regular  exercise on physical fitness  is well documented. There  is  also  evidence  that  acute  and chronic  exercise  affect  platelet  activation  in  different  ways. Few studies  are  available  on  effect of  exercise  on  platelets  function. Therefore, present work has been undertaken  to study  the effect of   exercise on platelets.Materials and Methods. The  study  was  conducted  on  40  healthy  female  subjects  in  the   age group  of  20–25. Samples for platelet counts, were obtained  prior  to  training  and  after  12 wk. Data obtained was compiled using computer software MS Excel for Windows. Statistically significant differences among quantitative variables were evaluated by Independent t–test and with the help of SPSS software (version 20). A p–value less than 0.05 was considered as statistically significant.Conclusion.according to results of present study platelet count was found to be increased in subjects who did physical exercise for 12 weeks.