The fibrosis involved in gluteus maximus causing limitation of flexion and adduction of the hip has become a recognized clinical entity since the first report by Fernandez de Valderrma in 1969. Its most constant and characteristic histologic feature was substitution of the fibrous tissue in the definitive etiology was unknown but presumed to be multiple intramuscular injections. Authors present three cases of the fibrosis involving gluteus maximus. In two cases Z-lengthening was performed on the thickened fibrous bands with good results.