Relatively hydrophobic bile acids have been shown to produce some hepatotoxicity, whereas treatment with a more hydrophilic bile acid, ursodeoxycholic acid, has improved liver function indices in patients with certain chronic liver diseases. Taurine‐conjugated bile acids are more hydrophilic than glycine‐conjugated bile acids, and thus, taurine administration has also been suggested for the treatment of chronic hepatitis. To determine if taurine and ursodeoxycholic acid are beneficial and if their effects are additive, this double‐blind, randomized trial was conducted to compare the effects of ursodeoxycholic acid, taurine, and a combination of the two on indices of liver injury in 24 patients with chronic hepatitis. The subjects were assigned at random to two of the four following treatments: ursodeoxycholic acid (600 mg/d), taurine (1.5 g/d), ursodeoxycholic acid plus taurine (600 mg and 1.5 g/d) or placebo, given in two successive cycles of 2 months each, according to a balanced incomplete block design. As expected, ursodeoxycholic acid became the predominant bile acid in bile when administered alone or in combination with taurine, and taurine conjugate concentrations increased during taurine administration. Ursodeoxycholic acid reduced serum aminotransaminase and γ‐glutamyl transpeptidase activities significantly, whereas taurine did not. The effects of taurine and ursodeoxycholic acid were not significantly different from those produced by ursodeoxycholic acid alone. It is concluded that ursodeoxycholic acid, but not taurine, improves biochemical indices of liver injury in patients with chronic hepatitis.