Electromyograms of the parasternal intercostal muscles and of the diaphragm were obtained with surface electrodes in 20 patients with early flaccid hemiplegia due to cerebrovascular accident. In most patients, a striking reduction in activity was observed during voluntary inspirations in both the intercostal muscles and the diaphragm on the side of the paresis. These findings suggest that in most persons the respiratory muscles are innervated primarily by decussated fibers. Dysfunction of the respiratory muscles might be implicated in the respiratory tract infections of patients with early hemiplegia.