Globally, treatment uptake for hepatitis C virus (HCV) infection among HIV-HCV coinfected men who have sex with men (MSM) has substantially increased since the advent of interferon-free direct-acting antivirals (DAA). However, HIV-positive MSM who engage in high risk behaviours are at an increased risk of HCV reinfection post-treatment. The aim of this study was to investigate perceptions of HCV diagnosis, treatment and reinfection risk among HCV-HIV coinfected MSM who engage in drug use and/or high risk sexual behavior in Sydney, Australia. Participants were recruited from the Control and Elimination within AuStralia of HEpatitis C from people living with HIV (CEASE) cohort (n=402) who reported engaging in drug use and/or high risk sexual behavior for transmission of HCV infection. Participants were interviewed about their perceptions of HCV diagnosis, treatment, and reinfection risk. Interview data were transcribed, coded, and analyzed thematically. Of 33 participants interviewed (mean age 49 years), many participants were 'shocked' by their HCV diagnosis. Participants who believed they acquired HCV infection through sexual exposure felt it was important that their healthcare practitioner agreed with their perspective to mitigate stigmatizing experiences. Overall, participants expressed high satisfaction with their treatment experience due to long-standing therapeutic relationships with their HIV physician. Many participants expressed knowledge of how to prevent HCV reinfection from injection drug use, yet other than condom usage, most were unsure how to reduce high risk sexual activity with such discussions occurring less frequently with healthcare practitioners. Findings indicate that MSM who engage in drug use and high risk sexual activity would benefit from additional education on reducing reinfection risk through sexual activity and services to reduce substance use, if requested.