High resolution single photon emission computed tomography (SPECT) was used to evaluate regional cerebral blood flow (rCBF) in 14 acutely depressed elderly patients and 29 normal subjects. SPECT images of the two groups were randomized and blindly read. Foci of decreased radionuclide uptake were assessed by number and location. The total number of rCBF defects per whole brain study was significantly greater in the depressed patients than in the normal subjects. A significantly greater number of rCBF defects was found most strikingly in the lateral frontal and less prominently in the lateral and medial temporal brain regions of the depressed patients.