Diabetes self-management (DSM) is a complex behavior and various factors influence it. Despite continual recommendations to DSM, implementation of this behavior still remains a major health problem for diabetic patients. Identifying effective factors in DSM is useful to promote health in diabetic patients. The purpose of this study was to test the effects of individual and environmental factors on DSM. Path analysis was used to examine both one-way direct and indirect effects of 7 constructs and 3 demographic factors on DSM in this population (N = 396). Data were collected from a convenience sample of 104 (26.3%) males and 292 (73.7%) females with a median age 53 years. The final model provided a good fit to the data explaining 25% of the variance in DSM. Illness perception and provider–patient communication were the most effective factors in DSM. Knowledge and self-efficacy affected DSM indirectly via illness perception. The results of this study showed that effective DSM interventions should be designed to change illness perception and patient–provider communication, especially in patients with low duration of diabetes and low level of education.