Secondary rhabdomyosarcoma (RMS) after treatment of osteosarcoma (OS) is rare. Reported here is the case of a metachronous RMS in the nasal cavity, developing 12 years after successful treatment of non-metastatic OS. The patient was diagnosed as having OS of the femur at 2 years of age. Chemotherapy for OS included doxorubicin (cumulative dose, 488 mg/m(2)). No radiotherapy was given. There was no family history suggestive of cancer predisposition syndrome. At 14 years of age, alveolar RMS was diagnosed on histopathology. PAX3-FKHR fusion transcripts were detected on reverse transcription-polymerase chain reaction. Germline TP53 mutation was not seen on standard DNA sequencing. The occurrence of secondary sarcomas, in the Children's Cancer Survivor study conducted in North America, has been associated with high cumulative doses of anthracyclines, which may also have played a role in the development of RMS in the present case. In the future, novel molecular technologies might uncover genetic cancer predisposition in patients with metachronous cancers.