Cystic hygroma is a rarc congenital malformation of the lymphatic system and seen rarely in adults. It represents an error in communication between the large draining lymphatic channels and the venous system, Conventional surgical excision remains the most popular method of treatment in many developing countries despite the dangers associated with treatment modality. We present a case of huge cervical cystic hygroma in a 26-year old female who was treated with OK-432 sclerotherapy.