The fourth branchial clef cyst is very rare entity ana only 35 cases have been reported worldwide. There have been some controversial attempts to prove its anatomical route through embryological background. However some reports even suggested that it might be impossible to prove its entity anatomically Recently, reports are coming out on the diagnostic approaches using anatomical pathway. We experienced in 45 years old woman, one case of lateral cystic neck mass which were anatomically presumed to be fourth brachial cleft cyst.