Although atazanavir is widely used in hepatitis C virus (HCV)-HIV-1 patients, little is known about its safety in advanced liver disease. We studied 34 HCV-HIV-1 patients with cirrhosis receiving atazanavir. After 551.2 patient-months of follow-up, there were no cases of serious liver toxicity or cirrhosis decompensation, and only 18.5% discontinued the drug. Despite median bilirubin level at inclusion was 1.5 mg/ml, increases in bilirubin level were mild. Model for end-stage liver disease score (MELD) increased to 1.35 points (95% confidence interval 0.13-2.6), but no patient changed their pretreatment situation after atazanavir introduction. Atazanavir is a well tolerated option in cirrhosis, and significant alterations in bilirubin or MELD were not observed.