A prospective six-month study was conducted to determine a high-risk index for medical rehabilitation patients who fall. Variables studied for all patients included demographics, medical conditions, associated symptoms, orthostatic blood pressure measurements, physical function, posture control, proprioception, use of physical restraints, and medications. A detailed examination of the fall events was also conducted. Of the 143 patients studied, 46 (32%) fell at least once, making a total of 84 falls. Impaired ability to follow directions, impaired judgment, impaired proprioception, presence of physical restraints, use of major tranquilizers, use of sedatives, and presence of psychiatric diagnosis were all individually associated with patients who fell. Males fell more than females. Logistic regression identified altered proprioception as the only major predictor of falling. Of those who fell, only 26% called for assistance prior to the fall. Sixty-eight percent of the falls were from wheelchairs. Importantly, no patients had serious injury or morbidity from the falls.