Thyroid diseases frequently accompany Cushing syndrome (CS). Nodular or diffuse goitre and autoimmune thyroid diseases may be evident during or after treatment of CS. A 29-year-old female presented with weight gain, hypertension and hirsutismus. Examinations revealed hypercortisolemia. Computed tomography revealed a solid mass 2.5-3 cm in size in the left surrenal gland and adrenalectomy was done. The diagnosis was adrenal cortical adenoma. A few days later she complained of pain in the left ear, neck, and head, which was diagnosed as subacute thyroiditis. To our knowledge, subacute thyroiditis accompanying CS is not reported in the literature before.