Cystic hygroma (CH) is a congenital malformation of the lymphatic system commonly treated with surgical excision. The typical locations of this lesion are the cervico-facial and cervicothoracic region and other rare locations include axilla, mediastinum, and limbs. CH usually presents at birth as a painless mass, which concerns parents. It might also be detected as complications resulting from it, such as respiratory distress fever, a sudden increase in the size, feeding difficulty, and infection. To the best of our knowledge, there are a few cases reported in cervico-axillo- thoracic variants and we reported giant cervico-axillo-thoracic cystic hygroma, which is thoroughly treated with surgical excision. A 45-days female, full-term delivery, infant presented with big right-side trunk mass, diagnosed through computed tomography scan as a CH involving the right lateral and posterior chest wall with extension to the axilla and right side of the neck, which was managed with surgical excision. After a 6-month of follow-up, no recurrent lesion masses were detected. CH is a congenital malformation of the lymphatic system that can be treated in the pediatric population. The treatment option depends on size, age, and location of the lesion. In our case, complete surgical excision was the selective treatment for this lesion.