Nearly all patients who undergo radical neck dissection note significant morbidity if the XIth cranial nerve is sacrificed. Physicians can be misled to believe in a lower morbidity because the usual physical examination is unreliable in detecting weakness and because patients rarely persist in mentioning shoulder problems during follow-up visits. Eleven patients between the ages of 55 and 70, who had undergone unilateral neck dissection with sacrifice of the XIth cranial nerve, were given questionnaires and were objectively evaluated for strength and active range of motion on a Cybex II dynamometer. Eighty-two percent of patients experienced pain, 91% experienced weakness, and 91% experienced impairment on the affected side. Peak torque for the affected side ranged between 0 to 85% of the peak torque for the normal shoulder. Gravity-free active range of motions were 20 degrees to 162 degrees with 8 of 11 at 100 degrees or less. In all but two patients, the passive range of motion was limited by pain.