This study identifies the acoustic characteristics of tones produced by Mandarin brain-damaged patients. We investigate the F0 characteristics of the patients’ tone productions and compare them with a control group of healthy speakers. The results show tone disruption in patients with brain damage in either the left or the right hemisphere. Even patients’ tone productions that were correctly identified by Mandarin native speakers were acoustically different from the ones produced by healthy speakers. The patterns of tone disruption in Mandarin brain-damaged patients might be caused by damage to the motor function in the brain.