BACKGROUND: Previous studies report that motor recovery after partial destruction of the primary motor cortex (M1) may be associated with adaptive functional reorganization within spared M1. OBJECTIVE: To test feasible methodologies for evaluating relationships between behavioral gains facilitated by rehabilitative training and functional adaptations in perilesional M1 and the cerebellum. METHODS: Four patients with hemiparesis for more than 3 months after a cortical lesion partially within M1 and 12 healthy volunteers participated. Functional magnetic resonance imaging (fMRI) using a finger-tapping task and concurrent behavioral assessments, including the Fugl-Meyer Motor Assessment of the upper extremity and the Wolf Motor Function Test, were conducted before and after 2 weeks of arm-focused training; 2 patients were further examined 6 and 12 months later to evaluate long-term persistence of brain-behavior adaptations. RESULTS: All patients showed higher activation magnitude in perilesional M1 than healthy controls before and after therapy. Further long-term functional gains paralleled the decrease of activation magnitude in perilesional M1 in the 2 more impaired cases. CONCLUSION: The evolution of suggestive correlations between serial scans of fMRI adaptive activity within the primary motor cortex and the cerebellum in relation to relevant behavioral changes over the course of 2 weeks of task-specific therapy and then no formal therapy suggests that repeated assessments may be best for monitoring therapy-induced neuroplasticity. This approach may help develop optimal rehabilitation strategies to maximize poststroke motor recovery as well as improve the search for brain-behavior correlations in functional neuroimaging research.