Cystic hygroma is known as lymphangioma which is a benign hamartomatous hyperplasia of lymphatic vessels. This tumour is thought to be developmental malformation of vessels which have poor communication with the normal lymphatic system. Most of the cases of cystic hygroma present before the age of 1-2 year. Only some cases of cystic hygroma present in childhood that enlarged in adulthood. Head and neck is the commonest site of occurrence. Many of this located in the posterior triangle of the neck. They may extend into oral tissues and oro-facial spaces. They may associated with macroglossia, mandibular prognathism, asymmetry of the face. They may cause respiratory embarrassment and dysphagia. We are reporting a case of cystic hygroma in an adult. Keywords: cystic hygroma, cystic lymphatic lesion, macrocystic lymphatic malformation, microcystic lymphangioma, cystic lymphangioma, lymphatic rests