Purpose This study aimed to investigate the effects of scapular stabilization training (SST) on trunk control and upper limb function in a patient with chronic stroke. Methods This case study involved a 53yearold female patient with rightsided hemiplegia following a left basal ganglia infarction. The intervention was conducted over four weeks, five sessions per week, for a total of 20 sessions, with each session lasting 60 minutes. Outcome measures included the trunk impairment scale (TIS) to assess trunk control, the reaching performance scale for stroke (RPSS) to evaluate reaching performance and compensatory movements, and the fuglmeyer assessment for the upper extremity (FMAUE) to assess upper limb motor function. All assessments were performed before and after the intervention under the same conditions. Results This study demonstrated improvements in dynamic sitting balance and trunk coordination following scapular stabilization training, with a 3point increase in the total TIS score. Reaching performance also improved, as reflected by increased RPSS scores and reduced compensatory trunk movements during both near and far reaching tasks. In addition, upper limb motor function improved, with a 6point increase in the total FMAUE score. Conclusion The findings of this case study suggest that scapular stabilization training may be an effective intervention in contributing to improvements in trunk control, reducing compensatory movements during reaching, and enhancing upper limb function in a patient with chronic stroke.