Background: The presence of hypoactive nodules in patients with Graves’ disease (GD) is an important factor in deciding on surgical treatment. Literatures are inconclusive about the increase in the risk of malignancy in cases of hypoactive nodules accompanying GD. The incidence of incidental malignancy in patients that underwent surgical treatment for GD were evaluated. Materials and Methods: This study included 108 patients that underwent thyroidectomy due to GD. Hypoactive nodules and diffuse hyperplasia were observed in 59 (54.6%) and 49 (45,4%) of the patients, respectively, during preoperative evaluation. In all 108 patients total thyroidectomy (TT) was the preferred surgical method. Results: Malignant histopathology was noted in 11 (10.2%) of the 108 patients. The thyroid nodules preoperatively observed in 59 patients were determined to be benign according to fine needle aspiration biopsy (FNAB), which also showed that 7 (11.9%) patients had incidental malignancy. Among the 49 patients with diffuse thyroid hyperplasia, but no nodule, 4 (8.2%) were incidentally malignant. Follicular and papillary carcin-omas were observed in 1 (9.1%) patient and 10 (90.9%) patients, respectively. Tumor size was ≤1 cm in 7 (70%) of the patients with papillary carcinoma. Hyperthy-roidism and recurrence were not observed in any of the patients with thyroid carcinoma during a mean follow-up of 27.3 months. Conclusions: The frequency of incidental thyroid cancer in patients with GD is unignorably high as the present study. The absence of nodules does not rule out the possibility of cancer. TT should be the preferred surgical treatment of GD.