Ollier's disease (enchondromatosis) is a nonhereditary disorder of mesodermal dysplasia. It is characterized by the presence of multiple enchondromas that typically affect the metaphyseal ends of bones. The association of Ollier's disease with adjacent fibromatosis has, to our knowledge, not been previously described. We report a case of Ollier's disease in association with soft tissue fibromatosis adjacent to the involved upper arm.