The intra-articular osteochondroma arising from soft tissue is very rare and has been reported less than a dozen cases in the English literature. This tumor is the result of extrasynovial metaplasia of the fibrous capsule or of the adjacent connective tissue of a joint. The authors experienced a case of giant intra-articular osteochondroma of the right knee in a 37 year-old man which arised from the medial meniscus. Histology as well as gross findings were consistent with osteochondroma. Excision of the mass with attached meniscus relieved symptoms. No recurrence, or malignant change was identified up to 1 year after excision.