The ABO system is the most important of all blood group systems because of presence of natural A and B antibodies in individuals who lack corresponding antigen on their red cells. This cross –sectional observational study, was conducted on 262 Medical and Dental students in the Department of Physiology, in a government Medical College in Kolkata, West Bengal. The frequency distribution of ABO and Rh system among the students were studied with respect to sex and religion for our institutional blood bank. ABO grouping and Rh typing were done by glass slide method. The study established that B positive (36.3%) was the commonest and AB negative (0.4%) group was least among the study population. Rhesus positivity were in 96.2% cases while Rhesus negativity in 3.8% . Rh positive individuals showed similar pattern of distributions like ABO group but in Rh negative individuals group O was predominant