Objective: To evaluate the effect of modified wheelchair arm-support to mitigate hemiplegic shoulder pain and reduce pain frequency in stroke patients. Design: A single-blind randomized controlled trial using computer-generated simple randomization. Setting: Participants recruited from inpatients at the Guangdong Provincial Hospital of Chinese Medicine. Subjects: A total of 120 patients with stroke were divided into two groups. Interventions: All subjects underwent basic rehabilitation training and wheelchair assistance with eight weeks follow-up period. Patients in the treatment group additionally received modified wheelchair arm-support for at least 60 minutes a day, six days a week, for four weeks. Outcome measures: Primary outcome was measured by the Visual Analogue Pain Scale or Numeric Pain Rating Scale. Secondary outcome was measured using the Upper Extremity Fugl-Meyer Assessment scale, Modified Barthel Index and Quality of Life Index. Measurements were made at 4 weeks and 12 weeks, following the intervention. Results: Patients age from 21 to 83 years (mean +/- SD = 62.41 +/- 12.26). The average duration of disease was 1.9 +/- 1.3 months. At four weeks, the median of pain intensity was higher in the control group (median, interquartile range = 3, 5.75 vs. 2, 3.75; P = 0.059). At 12 weeks, the median of pain intensity was higher in the control group (median, interquartile range = 3, 5.00 vs. 0, 1.00; P < 0.001). At 12 weeks, patients with shoulder pain were higher in the control group (6 vs. 1; P < 0.05). Conclusion: Using the modified wheelchair arm-support could lead to the mitigation of hemiplegic shoulder pain and reduction in pain incidence in stroke patients. It may also improve the patients' quality of life.