Neuropsychologists are increasingly involved in the assessment and treatment of individuals with glucocorticoid (GC) dysfunction. This review examines the clinical and neurophysiological changes associated with alterations in GC levels, with specific emphasis on changes in hippocampal plasticity and memory impairments. Hypothalamic-pituitary-adrenal (HPA) axis regulation of GC production and GC effects at hippocampal receptors are examined. GC-related changes in memory and hippocampal plasticity are considered in a wide array of populations, including animals, healthy adults, patients receiving exogenous GC treatments, and patients with neuropsychiatric disorders resulting in GC dysregulation. Hypotheses regarding GC-related memory changes are considered, with emphasis on hippocampal neurotoxicity and changes in excitatory amino acids, glucose metabolism and neurotrophic factors. These hypotheses are examined, with special attention given to inconsistencies and contradictions within this body of research. Finally, implications for neuropsychological evaluation and future research are presented.