Liver hemangiomatosis is defined as extensive hemangioma in the liver. Although hemangioma is the most common hepatic tumor, diffuse hepatic hemangiomatosis is very rare. Most cases of hepatic hemangiomatosis are seen in infancy, but it is extremely rare in adults. This is the first report, showing the enhanced growth of diffuse hepatic hemangiomatosis after hormone replacement therapy. We report herein two unrelated women, 47 and 42 year-old, from different regions of Turkey, who admitted to hospital because of right abdominal pain with diffuse hepatic hemangiomatosis, developed after hormone replacement therapy for menopause. The patients were healthy, except for hemangiomatosis, and their physical examination, routine laboratory tests, and tumor marker levels were within normal limits. It should be noted that their abdominal ultrasonography was normal before hormone therapy, but ultrasonography on admission revealed numerous, ill defined, diffusely located liver nodules in both patients. Dynamic magnetic resonance imaging and scintigraphy have revealed that these lesions are compatible with hemangiomatosis. These results suggest that hepatic hemangiomatosis was induced by estrogen therapy. Consequently, hormone replacement therapy was discontinued, and the patients were followed up for 3 years. Their physical examination and blood chemistry, including liver enzymes, remained within normal range, and the follow-up examination with ultrasonography showed no changes in size of lesions. Because of the possible association of hemangioma with estrogen administration, decisions should be made carefully about estrogen therapy for patients who already have hemangioma, and the periodic ultrasonograpy examination should be planned to detect possible new growth of liver hemangiomatosis.