Branchial cleft cyst is rarely encounted congenital neck disease. It is commonly believed that the branchial anomaly are persistance of remnants of the embryologic branchial apparatus. It is asymptomatic, or may be initially descriptive painless mass located superficially. In most cases, clinically they present after secondary infection. For the proper diagnosis and appropriate treatment of these anomaly, it is important things thar is appropriate index of suspicion for its existence, the understanding of the embryologic development and related surgical anatomy of the branchial cleft cyst are essential. The final diagnosis is confirmed by histopathologic study. Among the patients visited Kyung Hee Medical Center with neck mass and inflammatory sign from January, 1980 to May, 1990, we review 20 cases of branchial cleft cysts that are confirmed by histopathologic finding with retrospective study on clinical aspects. The result as follows : 1) Sex distribution was 11 malas and 9 females. Age distribution was most common in 2rd and 4th decade, which was 17 cases(85%). 2) The chief complaints were palpable mass in 8 cases, growing mass in 7 case in order and duration from the development of symptom to the first visit at OPD was variable from 20 days to 14 years. 3) In physical examination, the characteristics of the mass was non-tender(80%), mobile(90%), soft(95%) fluctuant. 4) The most common lesion site was anterior triangle in 10 cases. According to SCM level, upper 1/3 in 15 cases(75%), lower 1/3 in 3 cases, mid 1/3 in 2 cases. 5) In clinical menifestation, tuberculous adenitis in 6 cases, branchial cleft cysts in 5 cases and thyroglossal duct cyst in 2 cases in order. 6) Among 20 cases, fistulous tract was found in 4 cases : complete type in 1 case, incomplete type in 3 case. According to Work or Baily's brachial cleft sinus tract classification, type II in 3 cases type III in 1 case. 7) Branchial cleft cyst that according to Baily's classification, type II in 16 cases(80%), type I in 3 cases, type III in 1 case. 8) Type of lining epithelium in histopathologic finding was stratified squamous epithelium in 15 cases(75%), mixed type in 4 cases, no definitive epithelium in 1 case.