Extraskeletal osteosarcoma is an uncommon tumor originated from soft tissue without evidence of skeletal involvement. It usually affects adults and its common locations are extremity, buttock, and retroperitoneum. Although the histologic feature of this tumor is well known, there have been few reports on the fine needle aspiration cytologic findings. We report the imprint cytologic feature of extraskeletal osteosarcoma. The patient was a 49-year-old man with a mass of the left anterior chest for 2 years. On the imprint preparation, the smears showed malignant round, polygonal or spindle cells with coarsely clumped chromatin and occasionally prominent nucleoli. The malignant cells occur singly, in clusters, or associated with amorphous eosinophilic osteoid. Mitotic figures are also seen.