Steroids are commonly used in the treatment of acute spinal cord injury patients although a review of the literature fails to define a consistent regimen for administration with regard to optimal preparation or dosage or schedule. This study was designed to evaluate the effect of exogenous steroids on the outcome of experimental spinal cord injury and the effect of experimental spinal cord injury on endogenous cortisol production. Thirty female rhesus monkeys received a 660 gm cm lesion to the T10 spinal cord. They were randomly placed into one of six groups of five animals each. Two groups were controls used to assess the endogenous cortisol response to spinal cord injury. These animals received no steroids. The other four groups received one of two commonly used steroid preparations. All animals were evaluated serially for neurological status using motor testing and for general physical status. Serial cortisol determinations were obtained for an eight-week post injury period. The steroid groups showed some benefit from treatment when compared to the untreated controls. There were no significant differences in physical condition between treated and control groups. Of special interest was the response of endogenous cortisol production to spinal cord injury. Early cortisol elevation following injury peaked by eight hours and then precipitously dropped to baseline levels before 24 hours following injury.