Cystic hygroma, a variant of lymphangioma is a benign infiltrative tumor of lymphatic channels mainly occurs as congenital. It commonly occurs in neck, axilla, mediastinum and retroperitoneum. It may also occur secondary to trauma, infection, inflammation or degeneration. Cystic hygromas are rarely seen in adults and presentation in the upper limb is uncommon. We report a rare case of a 20–year–old male who presented with a painless cystic swelling in the left forearm. Ultrasonography shows large cystic lesion in the left forearm and proceeded with the surgery. Histopathological examination of excised cystic mass showed it to be a lymphatic malformation (cystic hygroma) of forearm. Complete surgical excision of lymphangioma done to prevent recurrence