BACKGROUND AND PURPOSE: Autonomic dysfunction has been described as a frequent complication of stroke that could involve the cardiac, respiratory, sudomotor, and sexual systems. Cardiac autonomic dysfunction after stroke is one of the most recognized and has been described to increase the rate of mortality and morbidity. METHODS: We report two cases of stroke-one hemorrhagic and one ischemic-and describe heart rate variability during the patients\' hospitalizations with improvement reported for each patient several days after stroke onset. RESULTS: The first case demonstrated autonomic dysfunction with severe reduction of HRV after a right parietal hemorrhagic stroke. The second case demonstrated similar findings in a patient with acute ischemic stroke. In both cases, normalization of heart rate variability occurred several weeks after stroke symptoms onset and was paralleled by a dramatic improvement of the clinical status. CONCLUSION: Our data established that serial HRV testing is a noninvasive tool that could be utilized as a marker to evaluate the dynamics of acute stroke.