Lipoblastoma is a rare benign tumor of the soft tissue occurring predominantly during the first two years of life. We report here the application of MRI and ultrasound to the detection of a soft tissue lipoblastoma. By MRI and ultrasound, we precisely evaluated the extent of the tumor, the presence of atypical areas of cystic and mucoid degeneration within the tumor, and its lack of vascularity. Our patient's lipoblastoma did not demonstrate the signal characteristics of a fatty tumor on MRI.