[Purpose] The purpose is to analyze the effects of Constraint-induced Movement Therapy in post stroke patients in chronic course. [Subjects and Methods] This is a Quasi-experiment study and the adopted protocol consisted of a three-hour therapy for ten consecutive working days applied to a constraint intact upper limb. Surface Electromyography, Motor Activity Log, Wolf Motor Function Test and Functional Independence Measure were used for evaluating the experiment. [Results] The individuals showed reduction in the degree of spasticity, confirmed by Surface Electromyography. In relation to Motor Activity Log this study showed an increase in amount and in quality of the paretic upper limb movement. The Wolf Motor Function Test showed reduction in the average time to perform the tasks and a functional improvement was identified through the Functional Independence Measure. [Conclusion] Constraint Induced Movement Therapy proved to be a relevant method to improve motor function in chronic hemiparesis post stroke reducing the spasticity, maximizing and improving the use of committed upper limb.