The ABO blood groups and their relationship with Australia antigen (HBsAg) were studied in 500 blood donors and 76 patients. Most of the blood donors belonged to group 'B' while the Australia antigen (HBsAg) was prevalent in the blood group 'A' (9.30%). 76 patients clinically diagnosed as viral hepatitis showed a similar trend, having the highest percentage of HBsAg positivity in 'A' group (35.71%). In both, this was found statistically significant (P greater than 0.005). None of those with AB blood group showed HBsAg.