Plexiform neurofibromas are benign tumors originating from subcutaneous or visceral peripheral nerves, which are usually associated with neurofibromatosis type 1. They are almost always congenital lesions and often cause the surrounding soft tissue and bone to grow aberrantly. We treated a 12-year-old boy who presented with asymmetric pectus excavaum and an anterior chest wall plexiform neurofibroma. The pectus excavaum was corrected by modified Nuss procedure, followed by simultaneous resection of the giant mass. The patient is doing well at the 4 years follow-up visit.