The adult rhabdomyoma is a rare, benign skeletal muscle neoplasm. The presented case involves a 56 years old patient who applied to hospital with a mass located in the right neck. The lesion was initially misinterpreted as a nodule of the thyroid gland as a result of physical displacement of the right thyroid lobe by a mass determined by ultrasound and CT scan. An adult rhabdomyoma located in close proximity to the thyroid gland and the most important differential diagnoses are discussed.