The purpose of this study was to investigate the effects of walking aid on hemiplegic gait of chronic stroke patients. Twelve stroke patients participated in this study. Physiological cost index (PCI), gait speed, and climbing stairs with and without walking aid were measured and analyzed. The results showed that walking with walking aid significantly improved gait speed and reduced physiological cost index and time needed to climb stair (height 7 cm) in comparison with a walking without walking aid. In conclusion, walking aid may improve the speed and efficiency of hemiplegic gait in chronic stroke patients.