Objective: The present study was aimed at investigating the effect of peer group-based training (PGBT) using the health belief model (HBM) on the quality of life (QOL) and foot ulcer self-care behavior in patients with type 2 diabetes. Materials and methods: The present study was a randomized controlled clinical trial performed on patients with type 2 diabetes who were referred to the Diabetic Care Clinic in Shiraz (Iran) from September 2019 to June 2020. A total of 70 patients participated in the study and were randomly assigned to peer training (n = 35) and control groups (n = 35). Diabetes Quality of Life, and diabetes self‑care behaviors, which were completed by both groups before, immediately, 1 month, and 3 months after the intervention. The data were analyzed using the Chi‑square test, paired t-test, independent t‑test, ANOVA, and descriptive statistical methods. P < 0.05 was considered statistically significant. Results: The results showed that mean scores of QOL, constructs of HBM (awareness, perceived susceptibility, perceives severity, perceived benefit, self-care behavior, and foot care) before the intervention did not reveal a significant difference between the two groups, but immediately one month after the educational intervention, the mean values for the intervention group were significantly higher than the control group (p < 0.05). Conclusions: PGBT using HBM was effective in increasing the mean score of QOL and self-care behavior in patients with type 2 diabetes. Thus, this method is recommended to be utilized alongside other methods to train patients.