OBJECTIVE Interferon therapy has been associated with a number of severe side effects when administered to patients with decompensated cirrhosis caused by chronic hepatitis B. The safety and potential efficacy of a low-dose, titratable regimen of interferon alfa-2b in patients with decompensated liver disease caused by chronic hepatitis B virus infection were studied. METHODS Twenty-six patients were treated at five medical centers. Five patients had Child's class A status, 15 had Child's B status, and 6 had Child's C status. Treatment was continued for 24 weeks whenever possible. Dose adjustments were made according to predefined safety criteria. RESULTS All patients with Child's A status responded with a sustained loss of serum hepatitis B virus DNA, reduction in aminotransferase activity, and clinical stabilization. Only 5 patients with Child's B (33%) and no patients with Child's C status reached similar end points. The probability of survival was greater in responders than in nonresponders (P = 0.017). Three patients each developed serious infections or greater than twofold increases in serum aminotransferase levels during therapy. CONCLUSIONS Low-dose, titratable interferon therapy is safer than previously reported regimens. Nonetheless, serious infections were observed relatively frequently, and this therapy should be reserved for individuals with mild to moderate hepatic decompensation, preferably patients with Child's A status.