This article presents our experiences from fixation of the sacrum by transiliacal screw in 13 patients with unstable fractures of the pelvic ring. Early mobilization, with no secondary dislocation or postoperative complications, was achieved in all patients. Sagittal instability in unstable pelvic ring fractures must be acknowledged. The transiliac screw offers the possibility of early mobilization of patients with this fracture. The procedure is demanding and patients selected for this treatment should be referred to hospitals with experience in the treatment of pelvic fractures.