Background: Acquired cystic hygroma is unusual in adults and most of these lesions are found in the posterior triangle of the head and neck region. Onset in adults may be secondary to trauma, infection or blockage of lymphatics. Complete surgical excision is the treatment of choice in adults. Case Report: We report our encounter and surgical management of a female adult Nigerian with a long-standing acquired cervical cystic hygroma. The patient underwent complete surgical excision by transverse neck incision without any clinical recurrence or neurologic sequelae at follow-up. Conclusion: Total surgical excision is treatment of choice for acquired cystic hygroma.