Lipoblastoma is a rare benign pediatric soft tissue tumor, and only two cases have been reported in Taiwan. We present the case of a one-year-old boy with a fast-growing soft tissue tumor in the right thigh. Magnetic Resonance Image (MRI) study showed a well-defined, lobulated, soft tissue tumor with fatty and myxoid components in the anterior lateral compart-ment of theright thigh. The tumor was completely excised. Histopathological study revealed a benign lipoblastoma. The case is discussed and the previous literature is reviewed.