Abstract: Introduction and aim: One of the problems of the diabetic community is thyroid disorders, which doubles the problems of these patients. The present study was conducted to investigate the prevalence of thyroid disorders in diabetic patients and related factors. Materials and Methods: In this cross-sectional study, 400 outpatients with diabetes, from 2014 to 2020, were selected by available sampling method and after extracting information and clinical and laboratory data from the clinical records of research units, the frequency of effective variables was analyzed using statistical analysis software. Results: The findings of the present study demonstrated that 142 patients (35.5%) had thyroid disorders; The most common thyroid disorders were clinical hypothyroidism (22.0%), subclinical hypothyroidism (11.0%), and hyperthyroidism (2.5%), respectively. Also, 49 patients (32.4%) had high anti-TPO antibody titers and among the patients with positive anti-TPO antibodies, 91.8% (45 patients) had thyroid disorders. There was a statistically significant relationship between the level of anti-TPO and the type of thyroid disorder in diabetic patients (P 00 0.001); Thus, 16.3% had Hashimoto's disease and 6.1% had Graves' disease. Conclusion: Thyroid disorders are relatively common in diabetic patients. Due to the high prevalence of diabetes in Iran, knowing the epidemiology of thyroid disorders in diabetic patients can help long-term planning for diagnosis, prevention, and early treatment of these disorders.