This study was designed to assess satisfaction with methadone treatment (MT) in a multidimensional manner among prison inmates and to identify significant independent predictors of inmates’ satisfaction with MT. A total of 158 prison inmates, who were currently on MT for at least the past 3 months, were assessed with the Verona Service Satisfaction Scale for MT. Inmate participants reported slight satisfaction with MT (3.1 on a 1-5 scale), with 51.3% of them feeling dissatisfied. Three factors were found to be independently associated with satisfaction with MT: HIV infection, odds ratio (OR) = 3.72, 95% confidence interval (CI) = [1.79, 7.73]; number of MT episodes, OR = 0.68, 95% CI = [0.53, 0.88]; and perceived influence on methadone dose changes, OR = 1.69, 95% CI = [1.25, 2.28]. Given that perceived involvement in treatment decisions is the only variable independently associated with MT satisfaction that can be modified by changing how MT is implemented, patient participation should be promoted and supported.