STUDY DESIGN: Cases report OBJECTIVES: We report 1 case of relatively rare osteochondroma that was in thoracic spine. SUMMARY OF LITERATURE REVIEW: Osteochondroma is one of the most common benign tumor in bone, consist of 40%, but, rare in spine area occupying only 2%. We report a case of osteochondroma that was in the 12th vertebra of thoracic spine, that had severe right flank pain. We performed en bloc excisional biopsy of the bony mass. MATERIALS AND METHODS: A fourty seven-year-old male complained right flank pain. He had mass of 12th thoracic costovertebral junction and underwent open excision and biopsy. RESULTS: The preoperative pain disappeared and any signs of recurrence were not found on the follow up performed at 1 year. CONCLUSIONS: The painful osteochondroma of thoracic spine is treated successfully by surgical technique.