The initial description of Carney complex (CNC) in 1985 included myxomas, spotty skin pigmentation, and endocrine overactivity (of the adrenal, the pituitary, and the testis). In 1997, thyroid neoplasms were found in 3 patients with CNC and involvement of the gland in the syndrome was apparent. Herein, we describe the clinical, pathologic, and follow-up findings in 26 patients with CNC and a disorder of the thyroid gland. The patients were predominantly middle-aged women with an asymptomatic thyroid mass. Four patients had hyperthyroidism, which was caused by follicular hyperplasia in 2 patients and by toxic adenoma in 2 others. Pathologic findings included benign lesions (follicular hyperplasia, nodular hyperplasia, and follicular adenoma) in 16 patients and carcinomas (follicular or papillary) in 10 patients. The follicular carcinomas had unusual features, multifocality, bilaterality, and lymph node metastasis. The tumor was fatal in 3 of 4 patients with a tumor ≥3 cm in diameter. One patient had an unusual multifocal microscopic follicular hyperplasia. Detection and treatment of the thyroid neoplasms in patients with CNC requires long-term follow-up of patients with the syndrome.