OBJECTIVE Thyroid disorders during pregnancy are important health problems worldwide. The aim of this study was to assess the knowledge of general practitioners (GPs) about thyroid disorders during pregnancy. METHODS In this cross sectional study, 120 GPs were randomly selected among participants of a continuous medical education (CME) program, entitled "practical endocrinology". To assess the knowledge and educational requirements of GPs regarding thyroid disorders during pregnancy, a validated and localized multiple-choice questionnaire was used. RESULTS A total of 100 GPs completed the questionnaire. The mean age of the participants was 37.0 years, and 41.4% were men. The mean knowledge score of GPs was 39.9%. On average, the rate of correct response to questions concerning the definition, pathophysiology, diagnosis, complications, and treatment of thyroid disorders was 39.0%, 39.3%, 48.8%, 34.3%, and 44.6%, respectively. There was a significant difference in knowledge among GPs, who had and had not passed the training course on thyroid disorders. In addition, GPs who had passed continuous medical education programs obtained higher knowledge scores regarding diagnosis and treatment (P < 0.05). CONCLUSIONS GPs attending pregnant women in Iran lack sufficient information on the pathophysiology, diagnosis, and management of thyroid disorders during pregnancy. Considering the key role of GPs in the public healthcare system, design of high-quality educational programs and development of specific educational packages about thyroid disorders and pregnancy are necessary.