Twenty-eight patients were studied for regional cerebral blood flow changes as a result of chronic alcoholism. After the administration of 550 to 600 MBq Tc-99m HMPAO, tomographic slices were obtained using a SPECT camera. Eight regions per hemisphere were drawn on each transaxial section, and tracer redistribution was calculated for each region. Region-to-whole slice ratios were determined for each patient. Patients had significantly decreased frontal/whole slice (1 +/- 0.02) ratios in comparison with a normal group (p less than 0.01). Twenty-four out of 26 patients (85.7%) demonstrated abnormal rCBF. Eighteen out of 28 (64.3%) showed activity lower in the left hemisphere than in the right. Using CT parameters, 60% of the patients had either sulcal widening and/or ventricular enlargement. The frontal region and the left hemisphere were more affected by alcohol than other regions. More cerebral blood flow changes than morphologic changes were found caused by alcoholism.