Objective : We tested the effect of mirror treatment on patients with and without unilateral neglect over a period of 4 weeks. We also wanted to know the effect of mirror treatment with regards to improving upper extremity function and dealing with activities of daily living. Methods : Subjects were 10 hemiplegia patients with unilateral neglect and 10 hemiplegia patients without unilateral neglect. They visited the department of occupational therapy. We performed mirror treatment for 30 minutes, 5 times a week for 4 weeks. We used Albert Test to compare our results from before and after the treatment, Fugl-Meyer motor function Assessment(FMA) and Box & Block Test(BBT) for upper extremity function, and Functional Independence Measure(FIM) for activities of daily living. Results : The results showed that mirror treatment had an effect on stroke patients with unilateral neglect. The treatment also had an effect on upper extremity function and activities of daily living regardless of unilateral neglect. Conclusion : The mirror treatment showed improvements on upper extremity function and activities of daily life as well as a reduction in the unilateral neglect after a stroke. In conclusion, the mirror treatment is useful for recovering function and improvement and for helping the patients complete activities of daily living.