Because most HBV/HIV co-infected patients on combination antiretroviral therapy (cART) have suppressed HBV DNA and normal liver enzymes, the histologic spectrum of liver disease in HBV/HIV coinfection is poorly defined. To address this gap in knowledge, we conducted a prospective study to comprehensively characterize liver disease severity assessed by liver biopsy in a well-defined cohort of HBV/HIV patients in North America receiving cART. Adult HIV/HBsAg positive patients on stable cART were recruited. Demographic, clinical, serological, and virological data were collected. Liver histology was assessed by a central pathology committee. The association of demographic, clinical, serologic, and virologic characteristics with liver histology was assessed using logistic regression. In this cross-sectional analysis, the mean age of the cohort (N = 139) was 49 years; 92% were male, 51% were non-Hispanic black, 7% had at-risk alcohol use with a median duration of infections of 14 years. The median ALT was 28 IU/L and CD4 count was 568 cells/mm. Almost all (99%) were on cART. Three-fourths (75%) had undetectable HIV RNA (<20 copies/mL). HBeAg was positive in 62%, HBV DNA was below the limit of quantification (<20 IU/mL) in 57% and <1000 IU/ mL in 80%; 7% had incomplete viral suppression (HBV DNA ≥1000 IU/mL and HIV RNA <20 copies/mL). Liver histology (available in n = 114) showed significant periportal, lobular, and portal inflammation (scores ≥2) in 14%, 31%, and 22% respectively. Over a third (37%) had significant fibrosis (Ishak stage ≥2); 24% had advanced fibrosis (Ishak stage ≥3). Higher ALT (adjusted OR 1.19 per 10 IU/L; 95% CI [1.01, 1.41]; p = 0.03) and lower platelet count (adjusted OR 0.81 per 20,000 mm; 95% CI [0.67-0.97]; p = 0.02) but not HBV DNA were independently associated with advanced fibrosis. In this cohort of patients with HBV/HIV coinfection receiving long-term cART with viral suppression, we observed significant fibrosis in more than one-third of patients.