Hemangiomas are the most common benign tumors occurring in the liver. However, the natural history of hepatic hemangiomas has not been well defined. Four patients (3 women, 1 man) with recurrent giant liver hemangiomas underwent either surgical or radiation therapy as initial treatment for the primary tumor. The average time until recurrence was 14 years, and each tumor weighed more than 600 g. Each of the female patients had been given chronic estrogen (Premarin) replacement therapy. Three of the four patients underwent surgical resection for intractable symptoms or progressive enlargement. It is believed that estrogen replacement therapy may play a role in the pathogenesis of these tumors. Furthermore, operative intervention should be considered in patients with recurrent giant liver hemangioma.