[Purpose] The purpose of this research was to examine the effectiveness of modified constraint-induced movement therapy (mCIMT) on the upper extremity function and occupational performance of stroke patients. [Participants and Methods] An experimental study was carried out on two groups of 7 participants selected by a specific criterion. The experimental group received the mCIMT as well as the conventional rehabilitation therapy (CRT) for 5 days per week over a 2 week period. The control group received only the CRT. Outcome measures included the Manual Function Test (MFT), Motor Activity Log (MAL), and Canadian Occupational Performance Measure (COPM). [Results] Average amount of changes in the MAL and COPM is different in statistical analysis between the mCIMT and the CRT groups before and after the intervention. The mCIMT group showed significant improvements on MFT, MAL, and COPM before and after the intervention. [Conclusion] We suggest that the mCIMT improves the upper extremity function and occupational performance of stroke patients better than the CRT alone.