Myositis ossificans is a rare condition characterized by non-neoplastic heterotopic bone formation in soft tissue and skeletal muscle. It is a benign and often self-limiting disease with no need for surgery. Here, we describe a young female swimmer with myositis ossificans circumscripta of the triceps due to overuse. Because of the benign character of the lesion, conservative treatment was initiated with rest and anti-inflammatory drugs. She obtained complete resolution after 6 months and was able to return to normal sporting activities. Myositis ossificans circumscripta is a rare benign lesion with an excellent prognosis. Most lesions in athletes occur due to contusions or strains; however, overuse is now described as well. Spontaneous resolution is seen in almost all cases. Cases in which, despite conservative treatment, a painful mass persists, surgical excision can be considered.