We report the case of a painless deforming subungual mass at the nail tip, progressively enlarging over three months. Radiographs showed an extra-osseous ossification. Intraoperatively this was found to be a bony mass arising from the sterile matrix. Unusual extra-osseous ossification in the finger is rare and this case highlights the need of this benign lesion to be considered when a patient presents with finger swellings.