The glucocorticoid cascade hypothesis proposes that hippocampal atrophy may result from excessive steroid exposure. Although demonstrated in animal models and some human hypercortisolemic states, hippocampal damage as a possible consequence of posttransplant steroid immunosuppression has not been investigated in human heart transplant recipients. We report a case of a 37-year-old female heart transplant recipient who had the clinical, neuropsychiatric, and neuroimaging findings consistent with hippocampal atrophy after 5 years of steroid exposure.