: Hepatitis B (HBV) and C (HCV) virus coinfections remain major contributors to liver-related morbidity and mortality among people living with HIV (PLWH). This study aimed to assess the prevalence of HBV and/or HCV coinfections in a Romanian HIV cohort and to evaluate their impact on immunological, virological, and liver function parameters under antiretroviral therapy (ART). We retrospectively analyzed 462 HIV-infected patients (2018-2021) from the National Institute of Infectious Diseases, Bucharest, stratified into four groups: HIV mono-infection ( = 176), HIV/HBV ( = 114), HIV/HCV ( = 97), and HIV/HBV/HCV ( = 75) coinfections. Immunological (CD4 count, CD8 count, and CD4/CD8 ratio), virological (HIV-1 RNA), and hepatic parameters (ALT, AST, GGT, bilirubin, amylase, and lipase) were compared. No significant differences were observed between groups regarding the immune recovery (mean CD4 count = 0.89, HIV-RNA suppression = 0.78). However, liver and pancreatic parameters showed statistically significant deterioration in the coinfected groups. ALT ( < 0.001), GGT ( = 0.009), total bilirubin ( = 0.011), amylase ( = 0.010), and lipase ( < 0.001) were significantly higher in the triple-infection (HIV/HBV/HCV) group compared to HIV mono-infected patients. Coinfection was also associated with a longer duration of illness ( = 0.002) and therapy ( = 0.021) and with a higher number of ART regimens used ( = 0.013). While HIV suppression and immune recovery were not significantly impaired by HBV/HCV coinfections, liver and pancreatic injuries were significantly more prevalent and severe in coinfected patients. Regular monitoring of hepatic function and integrated management strategies are recommended to minimize liver-related complications in this population.