Enhanced feedback provided by a virtual reality system has been shown to promote motor learning in normal subjects. We evaluated whether this approach could be useful for treating patients with motor deficits following brain lesions. Fifty subjects with mild to intermediate arm impairments due to stroke were selected for the study. The patients received treatment daily for one month, consisting of an hour of virtual-environment therapy with enhanced feedback. Before and after the therapy, we assessed the degree of motor impairment and autonomy in daily living activities using the Fugl-Meyer scale for the upper extremities and Functional Independence Measure, respectively. We also analyzed the velocity, duration, and morphology of a sequence of reaching movements, finally comparing the kinematic measures with the scores obtained on the clinical scales. The rehabilitation therapy yielded significant improvements over baseline values in the mean scores on the Fugl-Meyer and Functional Independence Measure scales. The mean Fugl-Meyer score correlated significantly with the duration and velocity of reaching movements. The collated data indicate that motor recovery in post-stroke patients may be promoted by the enhanced feedback provided in a virtual environment and that kinematic analysis of their movements provides reliable measures of motor function changes in response to treatment.