Purpose The purpose of this study was to investigate the effects of trunk stabilization exercise on arm function, balance, and walking ability in stroke patients. Methods The subject was a 73yearold woman, and 4 weeks had elapsed from the date of onset due to a stroke caused by cerebral infarction on December 1, 2022. The left hemiplegia resulted in decreased arm function, balance, and walking ability. Intervention was conducted for 3 weeks with trunk stabilization exercise 3 times a week, 50 minutes per session. Results As a result, the arm function improved by 2 points in the Manual Function Test (MFT) (from 13 scores to 15 scores), and the Limit of stability (LOS) in Biorescue increased by 319.33㎟ area (from 941㎟ to 1260.33㎟). In addition, walking time in the 10M Walking Test (10MWT) was reduced by 4.63 seconds (from 18.55 seconds to 13.92 seconds). MFT, LOS, and 10MWT values were clinically significantly improved. Conclusions In conclusion, we suggest that trunk stabilization exercises can help improve arm function, balance, and walking ability. Further research is needed to generalize the results of this study.