Crack branchial cysts, described by Von Ascherson in 1932, are laterocervical masses coming from the abnormal development of a gill arch. Cysts of the 3rd and 4th branchial arch are extremely rare. Cysts of the third arch are related to the larynx and thyroid. Male patient of 14 years of age who is consulted by frame, which has provided nursing, consisting of the secretion of liquid with a characteristic mucous, the left lateral surface of the neck, presenting herself spontaneously and intermittently, without accompanying symptoms. On physical examination draws attention neck asymmetric expansion of the lesion in punctiform third anterior and lower sternocleidomastoid, which is palpable nodules in 5 mm, elastic solid consistency, rounded, subcutaneous, clear liquid with release of compression, is not to find significant adenopathy. Held notes and fistulography fistula with 3 cm medial and deep. Proceeds to the same surgical recession and finds a fornix blind to the thyroid and larynx. Anatomical pathology reports cyst lined by stratified columnar epithelium ductal type associated with the glandular acini mucoserosous compatible with cysts. Performs follow-up was uneventful.