Cystic hygroma (CH) is a benign, developmental condition of unknown etiology. 90% of the cases are present by age 2. CH represents malformed lymphatics that fail to communicate with larger veins and, therefore, they collect lymph. It is a type of lymphangioma. The clinical presentation is one of a painless, soft mass that reaches a giant size and can lead to the death of the infant. The diagnosis is done with CT scan and biopsy. We report a severe case of CH and describe the difficult surgical treatment, despite the benign nature of the lesion.