Objective: To assess predictors for adherence to a home-based pelvic floor muscle exercise (PFME) program supplemented with three physical therapy sessions in women with urinary incontinence (UI). Design: Secondary analysis of a randomized controlled trial of interventions to enhance self-efficacy with respect to PFME. Setting: Patients were referred from public primary or secondary care providers in Florianopolis, Brazil. Participants: Adult women with UI. Intervention: Three supervised physiotherapy sessions for the treatment of UI combined with home-based PFME program. Treatment groups were combined for predictive modelling because there was no difference after intervention between groups regarding UI and adherence rates. Main Outcome Measures: Adherence to PFME at 3-month follow-up (structured questionnaire). Baseline Predictors: self-efficacy and outcome expectation scales; severity of UI (ICIQ-SF), pelvic floor muscle strength, age, body mass index (BMI), and educational level. Results: 86 women with UI of whom 72 completed the study. An intention-to-treat analysis was performed. Forty-three women reported carrying out PFME every day. Adherence was correlated to: baseline self-efficacy (r = 0.299); age (r = 0.242); and educational level (r = -0.273). Hierarchical regression analyses incorporating treatment group, age, education, disease-related factors (severity of UI; pelvic floor muscle strength; BMI), and outcome expectations and self-efficacy showed that only baseline self-efficacy predicted adherence (R-2 = 0.217). Conclusions: Adherence to home-based PFME is a complex phenomenon. Assessing self-efficacy may help physiotherapists to detect patients' confidence in performing home-based exercises and, when necessary, give patients additional incentives.