Original Article introduCtionGraves' hyperthyroidism is the most common cause of hyperthyroidism. [1] Treatment options include antithyroid drugs (ATDs), radioactive iodine, or surgical resection, although none of these options target the mechanism of the disease, and there is no single treatment that can target both hyperthyroidism and the main extrathyroidal manifestation (orbitopathy). [2] ATDs act by inhibiting thyroid hormone synthesis, but they have some immunosuppressive action. In Europe and Japan, ATDs are still the first-line treatment, [1] but in North America, radioactive-iodine is much preferred. [3,4] Endocrinologists in the Middle East and North Africa (MENA) seemed to practice in a hybrid fashion between these two groups depending on previous training and current affiliations. [5] Background: Choice of the treatment for patients with Graves' hyperthyroidism depends on local preference, the higher recurrence risk, comorbidities, and the patient's preferences. About half of the patients relapse after a course of a standard antithyroid drug (ATD) therapy for Graves' disease. Objectives: The objective of this study was to determine the clinical and biochemical features of Graves' hyperthyroidism that can predict the relapse of the disease after a standard course of ATD therapy. Patients and Methods: We conducted a retrospective 6-month study of 79 patients with Graves' hyperthyroidism who were treated with ATD (carbimazole) therapy for 12-18 months and went into remission for at least 1 year after ATD withdrawal. Results: The relapse rate in Graves' hyperthyroidism after 1 year in remission was 40.5%; patients with younger age (<40 years) and with severe biochemical disease correlated significantly with relapse. Gender, presence of a palpable goiter, orbitopathy, and smoking habits were not significant predictors of relapse, perhaps because of the small sample size. Conclusions: Forty percent of Graves' hyperthyroidism relapsed after 1 year of remission. Younger age and severe biochemical disease at diagnosis predicted relapse.