Syncytial giant cell hepatitis (SGCH) among adult human immunodeficiency virus (HIV)-infected patients has been rarely described. Most cases have been reported in subjects coinfected with the hepatitis C virus (HCV), but its prevalence and outcome remain unknown. We performed a retrospective analysis of all cases of SGCH among 332 liver biopsies from HIV-infected patients seen at a tertiary center in Madrid, Spain, between 1984 and March 2004. Two hundred fifty specimens were obtained from HCV-coinfected patients. There were 2 cases of SGCH, leading to an observed overall prevalence of 0.6% (0.8% when considering only HCV-coinfected patients). In addition to histological changes secondary to chronic hepatitis C, the liver cords were replaced by syncytial giant cells with up to 30 nuclei. There was no histological evidence of measles (among paramyxoviruses) or herpes viruses group infections. In patient 1, there was a progressive clinical worsening after a 3-month course of prednisone, leading to liver failure and death. His postmortem liver biopsy showed more abundant giant hepatocytes accompanied with the development of a histologic pattern of severe fibrosing cholestatic hepatitis. The second patient received a prolonged course of pegylated interferon-alpha-2b and ribavirin with clearance of syncytial giant hepatocytes despite HCV-RNA persistence. SGCH is a rare histological finding among HIV-infected patients with chronic hepatitis C. Specific treatment with pegylated interferon and ribavirin can lead to histological resolution and biochemical improvement, even in the absence of HCV-RNA clearance.