Lipoblastoma and lipoblastomatosis are rare benign tumors of embryonal fat with a tendency to local invasion but not to metastasize. To date, there have been 60 cases described in the international literature. There has never been a report in a child older than 8 yr. The main clinical characteristics are the presentation, usually below 3 yr of age, the rapid growth of the mass and the peripheral location, mainly in the extremities. Although CT scan may show a fatty tumor, there is no single test to make the differential diagnosis (which includes benign lipoma, liposarcoma and myxoliposarcoma) and the treatment should be based on clinical findings. We have treated four patients with this condition. Two were intrathoracic, one was intraperitoneal, and one was a tumor of the upper arm. All presented as rapidly-growing tumors and were clinically assumed to be malignant. We recommend complete but conservative excision of the tumor; there are reported recurrences after inadequate excision. This is a benign tumor and radical cancer surgery should be avoided.