All 77 HBsAg positive and 94 of representative HBsAg negative sera derived from 253 adult patients with acute sporadic viral hepatitis during 1987 at Chandigarh were tested for serological markers of hepatitis B virus (HBV) and hepatitis A virus (HAV) infections. The HBsAg positive patients could be classified as acute hepatitis B (64%); chronic hepatitis B with exacerbation, or liver damage by other infectious or noninfectious agent/s over a chronic HBsAg carrier state (35%); and coinfection of HBV and HAV (1%). Among the HBsAg negative hepatitis group, acute hepatitis B was diagnosed in 4 per cent of patients and acute hepatitis A in another 4 per cent.