Objective To determine whether a modified cognitive-motor dual task training using traffic signals for stroke patients is effective in improving cognitive and motor abilities. Methods Sixty-four convalescent stroke patients with hemiplegia and cognitive impairment were randomized to be a control group or an intervention group, with 32 in each group.The control group received conventional physical therapy and occupational therapy, while the intervention group received a modified cognitive-motor dual task training using traffic signals in addition to the conventional therapies.The training lasted 4 weeks.Motor and cognitive functions were assessed in both groups before and immediately after the intervention. Results After the intervention, the time for the maximum walking speed test in the intervention group was significantly shorter than that in the control group (P＜0.05).The total score and scores of six dimensions (except for the abstraction dimension) of the Montreal Cognitive Assessment were significantly higher in the intervention group than those in the control group (all P＜0.05). Conclusion The modified cognitive-motor dual task training using traffic signals can effectively improve motor and cognitive functions of hemiplegic stroke patients.