Twenty eight years old female patient presents with 1cm in diameter, hard and painless swelling in the left side of the neck. On physical examination; 1cm in size, rigid, painless and fixed mass was detected in the left retromandibular area. Cervical computerized tomography (CT) scan was performed. The elongation of left transverse process of atlas giving misleadingly the impression of a neck mass was observed in CT scan. In the literature, the elongation of transverse process of the seventh cervical vertebra is common but clinical conditions depending on the elongation of transverse process of atlas is very rare. Surgical intervention was not considered because the patient does not have any complaint other than palpable mass. As in this case, elongated transverse process vertebra (atlas) as a rare condition must be kept in mind in the differential diagnosis of rigid and fixed neck masses.