Background: Diabetes is the most prevalent metabolic disease in human being. The lifestyle ofthis population is important and effective in the treatment process. Training is among the mostbasic methods of prevention, treatment and control of chronic diseases, including diabetes. Thisstudy was conducted to investigate the effect of teach-back method on health promoting lifestyleof people with diabetes. Methods: A total of 74 eligible patients with type II diabetes were included in the study fromEndocrine and Metabolism Clinic by convenience sampling method. The subjects were thenassigned into the control and intervention groups. The data collection instruments consisted of ademographic data form and Health Promoting Lifestyle Profile II (HPLP-II) that were providedto the subjects before and 1 month after the training. Subjects in the intervention group receiveda 4-session training program by means of teach-back method. The control group received onlyroutine programs. One month after the completion of the training sessions, the questionnaireswere completed by the subjects in the 2 groups. The obtained data were analyzed by Chi-squaretest, Fisher Exact test, Independent t-test, Paired t-test, Mann-Whitney U test, and Wilcoxonsigned-rank test, using SPSS. Results: The obtained results suggested no significant differences between the 2 groups in termsof demographic and dependent variables, before conducting the intervention. The Mean± SDscore of lifestyle was 113. 67± 19. 55 in the intervention group and 115. 35± 9. 73 in the controlgroup, before the training, which was not significant. However, there was a difference betweenthe Mean± SD score of lifestyle in the intervention group (160. 45± 10. 53) and control group(119. 59± 11. 23), 1 month after the training (P<0. 001). Conclusion: Teach-back method is appropriate and feasible for patients with diabetes and is aneffective method to improve the lifestyle of this population. This study was conducted over a1-month period, and it is recommended that the effect of this method be investigated over longerperiods of time in order to assess its long-term effects.