OBJECTIVE: Diabetes mellitus (DM) is a growing health problem with serious complications. The chronic and progressive nature of the disease often leads patients to use complementary and integrative medicine. The present study aimed to investigate the frequency of use of alternative medicine by patients with DM and the products used. METHODS: Between September 2014 and May 2015, 301 patients with DM were selected from Bezmialem Foundation University Hospital Diabetes Clinic to participate in the study.RESULTS: The results of the study indicate that 81 (26.9%) patients had tried alternative medicine, and 50 (16.6%) patients continued to use some form of alternative medicine product. A total of 43 (14.3%) patients used such products every day and 24 (8%) patients had used alternative medicine products for up to 6 months. Glycated hemoglobin (HbA1c) levels were significantly decreased in patients using alternative medicine products compared to the remainder of patients in the study (p=0.017). No other significant difference was found between the two groups. It was observed that among patients using alternative medicine products, only 10 (12%) had informed their physicians.CONCLUSION: This study indicated that patients with diabetes are very likely to use alternative medicine products. Additional studies are needed to further determine the efficacy of these products. Patients as well as health providers must be educated about complementary medicine and alternative products.