Objective To determine the clinical value of triple stimulation technique (TST) in the assessment of cortico-spinal tract impairment in patients with atypical parkinsonism. Methods Six patients with atypical parkinsonism (5 cases of parkinsonian variant of multiple system atrophy and 1 of progressive supranuclear palsy) admitted in our hospital in July 2009 were recruited in this study. Another 12 age-matched subjects (7 healthy volunteers and 5 non-central nervous system involvement patients) served as controls. All the subjects were examined with conventional motor evoked potential (MEP) test and TST at abductor digiti minimi. Resting motor threshold (RMT), central motor conduction time (CMCT), MEP latency and TST amplitude ratio (TSTtest/TSTcontrol) were assessed, and their correlation to the age and disease duration were analyzed. Results The TST amplitude ratio was significantly decreased [(40.7±18.6)% vs (96.8±3.0)%, P＝0.001] in atypical parkinsonism along with increased RMT [(63.3±5.2) vs (48.6±8.4), P＝0.001] when compared with controls. But there was no significant difference in CMCT and MEP latency between the 2 groups (P＞0.05). Neither conventional MEP nor TST showed significant correlation with age or disease duration, but TST amplitude ratio showed negative correlation trend with disease duration. Conclusion TST is superior to conventional MEP in the assessment of cortico-spinal tract impairment in atypical parkinsonism.