[Purpose] The purpose of this study was to determine the effect of action observation on walking performance and its clinical feasibility for treatment of hemiparetic stroke. [Subjects] The subjects of the study were 30 stroke patients. [Methods] They were randomly allocated to two groups: an experimental group (n=15) which used the action observation training and the control group (n=15) which did no exercise. [Result] The results indicate that step length (cm), stride length (cm), single support time (%), double support time (%), gait velocity (m/s), and cadence (steps/min) significantly improved in the experimental group. In contrast, in the control group, the results indicate that step length, stride length, single support time, double support time, gait velocity, and cadence did not significantly change. There were significant differences in step length, stride length, single support time, double support time, gait velocity, and cadence between the experimental group and the control group after the intervention of action observation. [Conclusion] These findings suggest that the action observation can enhance the walking performance of patients with post stroke hemiparesis.