Branchial cysts and fistulae in the lateral part of the neck are believed to arise from the same remnant of the branchial arches. The two lesions, however, are distinct and separate. Clinical findings of the fistulae could be related to the branchial apparatus. In contradistinction the age of manifestation, the localisation, the history, th symptoms and the histological features of the lateral cervical cysts disagree in regard to the branchial origin. That is why various congenital hypotheses are discussed and rejected, partly because the existence of stratified squamous cells in cervical lymph nodes present recent suggestions. The lateral lesions and dental cysts, especially radicular cysts, are compared. Both kinds of cystic structures are often associated with an initial infection.