Abstract Background Data on hepatitis C virus (HCV) reinfection in East Asian people with HIV after treatment-induced sustained virologic response (SVR) are limited. Methods HIV/HCV-coinfected patients in Taiwan who achieved SVR12 with interferon (IFN) or direct-acting antivirals (DAAs) between 2005 and 2021 underwent HCV RNA measurements at SVR24 and then biannually. HCV reinfection was defined as the detection of different HCV strains beyond SVR12. HIV-negative, low-risk individuals with SVR12 served as reference patients. Crude reinfection rates and secular trends were assessed. Multivariate Cox regression analysis was performed to identify baseline factors associated with HCV reinfection. Results A total of 216 HIV-positive and 1589 reference patients were recruited, with median follow-up durations of 3.0 and 6.0 years, respectively. During a total of 772 person-years of follow-up (PYFU), the HCV reinfection rate in HIV-positive patients was 4.02 per 100 PYFU (95% CI, 2.85–5.65), while the HCV reinfection rate in reference patients was 0.14 per 100 PYFU (95% CI, 0.09–0.23) during 10 862 PYFU. HIV-positive patients had a higher risk of HCV reinfection than reference patients (hazard ratio [HR], 17.63; 95% CI, 7.10–43.80; P < .001). No baseline factors were predictive of HCV reinfection in HIV-positive patients. The incidence of HCV reinfection in HIV-positive patients increased after 2015, when DAAs were made available in Taiwan. Conclusions The risk of HCV reinfection remains high in HIV/HCV-coinfected patients with treatment-induced SVR12. In addition to mass screening and treatment scale-up, strategies to reduce reinfection are needed for HCV microelimination in HIV-positive patients in Taiwan.