We prospectively evaluated the costs of medical care in a group of 43 patients with acute severe stroke. Patients were assigned to either a routine hospital bed or a rotational bed. The rotational study bed (kinetic therapy) is designed to prevent complications of prolonged bed confinement by keeping patients in continuous slow rotation. The average number of acute care days was 11.2 in the study group and 16.4 in the control group. Study patients had similar costs per day for laboratory testing, x-ray studies, respiratory therapy, total acute care expenses, and total hospital expenses. Among study patients, reduction in medication costs per day did approach statistical significance, by unpaired t test, at P =.014, with a corrected significance level of.008. Overall, the average acute care costs per day were $544 in the study group versus $410 in the control group. This difference was approximately the average per day charge for the rotational bed ($130). We conclude that therapy designed to prevent complications of prolonged bed confinement is cost effective. © 1990 Southern Medical Association.