Background and purpose. This study aims to determine the long-term effects of a new Memory Self-efficacy (MSE) training program for stroke patients on MSE, depression, and quality of life. Methods. In a randomized controlled trial, patients were allocated to a MSE training or a peer support group. Outcome measures were MSE, depression, and quality of life, measured with the Metamemory-In-Adulthood questionnaire, Center for Epidemiological Studies-Depression Scale (CES-D), and the Who-Qol Bref questionnaire, respectively. We used linear mixed models to compare the outcomes of both groups immediately after training, after 6 months, and after 12 months, adjusted for baseline. Results. In total, 153 former inpatients from 2 rehabilitation centers were randomized-77 to the experimental and 76 to the control group. MSE increased significantly more in the experimental group and remained significantly higher than in the control group after 6 and 12 months (B = 0.42; P =.010). Psychological quality of life also increased more in the experimental group but not significantly (B = 0.09; P =.077). However, in the younger subgroup of patients (<65 years old), psychological quality of life significantly improved in the experimental group compared to the control group and remained significantly higher over time (B = 0.14; P = .030). Other outcome measures were not significantly different between both groups. Conclusions. An MSE training program improved MSE and psychological quality of life in stroke patients aged <65 years. These effects persisted during 12 months of follow-up.