Summary. We evaluated tolerability and virological and clinical impact of anti-Hepatitis B Virus (HBV) nucleos(t)ide analogues in cirrhotic patients with HBV/Hepatitis C Virus (HCV) coinfection. The virological and clinical course of 24 consecutive HBsAg/HBV-DNA/anti-HCV-positive patients with cirrhosis was compared with that of 24 HBsAg/HBV-DNA-positive, anti-HCV-negative cirrhotic patients, pair-matched for age (±5 years), sex, HBeAg/anti-HBe status and Child-Pugh class. Patients in both groups were previously untreated with oral antiviral agents at enrolment and were treated for at least 24 months (range 24–54). At the 12th and 18th month of treatment, HBV-DNA was negative in 21 (87.5%) and 23 (95.8%) patients with hepatitis B and C and in 20 (83.3%) and 22 (91.6%) in patients with isolated HBV; all patients in both groups were HBV-DNA-negative at month 24 and at subsequent observations. Treatment was well tolerated by all patients in both groups. At the last observation (for co-infected patients, median 44 months and range 24–54; for mono-infected patients, median 40 months and range 24–54), a deterioration in Child class was observed in eight (47%) of 17 patients in patients with both HBV and HCV who were HCV-RNA-positive at baseline, but in none of seven HCV-RNA-negative patients in the same group, and in one patient (4.2%) in the mono-infected patients. Reactivation of HCV infection was relatively infrequent (12.5% of cases) and never associated with a clinical deterioration. Treatment with nucleotides in HBsAg/HBV-DNA/anti-HCV-positive patients with cirrhosis showed a favourable virological effect in all cases, but a favourable clinical result only in the HCV-RNA-negative at baseline.