Numerous studies of glucorticoid receptors in the rodent brain suggest that similar studies of normal or diseased human brains might be informative. However, a major confound in quantification of such receptors is their possible decay during the lagtime between death and autopsy. We find evidence for such decay. Assay conditions were optimized in a number of ways to remove endogenous glucocorticoids occupying receptors at the time of death. Despite this, [3H]dexamethasone binding in 3-4.5 h postmortem human hippocampus was approximately half that of fresh human primate tissue, while no binding was detectable in 12-24 h postmortem material. In support of the idea of postmortem decay of these receptors, binding in slices of primate temporal cortex left at room temperature declined approximately 50% by 6 h postmortem.