The value of the hepatic venous pressure gradient, measured during a transjugular liver biopsy procedure, was evaluated in the differential diagnosis of chronic persistent versus active hepatitis. The diagnosis of chronic persistent or active hepatitis was carried out according to classical clinical, biological, and above all pathological criteria. Patients with chronic active hepatitis were divided in to subgroups according to the degree of aggressivity and the presence of cirrhosis. Of the 70 patients studied, 13 had a gradient lower than 0.79 kPa, and all had chronic persistent hepatitis; 48 patients had a gradient higher than 0.93 kPa, they all had a chronic active hepatitis. For the 9 remaining patients, the gradient was between 0.79 and 0.93 kPa, 3 had persistent hepatitis, and 6 had active hepatitis. There was no significant variation of the gradient according to aggressivity in the subgroups of chronic active hepatitis. The gradient separated clearly chronic active hepatitis with or without cirrhosis. The measurement of the hepatic venous pressure gradient allows to differentiate between chronic persistent versus active hepatitis in 87 p. 100 of cases. This simple procedure offers a quick clue to diagnosis before obtaining histologic results.