Myositis ossificans progressiva (MOP) is an autosomal dominant disorder. There is a progressive ectopic ossification and skeletal malformation, mainly in the connective tissue of muscle. The diagnosis is based on the clinical findings and radiological demonstration of the skeletal malformations. A 38-year-old female patient was admitted to our department with progressive increase of the thigh. Results of laboratory studies were normal. The radiography of the right thigh showed multiple intramuscular calcifications. Myositis ossificans progressiva should be diagnosed as early as possible and non-invasively, based upon history, clinical and radiological findings. Early and correct diagnosis is fundamental for indication of proper management of the disease.