In this case report, we examine Franklin Delano Roosevelt's prognosis, clinical course, and rehabilitation from poliomyelitis, and we examine the criticisms of errors in his diagnosis and management on the basis of current knowledge of the pathophysiology of poliomyelitis. Medical and historical records reveal the onset of severe paralysis, which progressed over several days, with minimal improvement in hips and lower limbs, but recovery of facial, upper limb, and upper trunk muscles. There is no scientific basis for assertions of mismanagement that led to more severe paralysis; the paralysis was most likely caused by strenuous activities in the preparalytic phase of his illness.