Twelve patients with a diagnosis of schizophrenia and thirteen control subjects were injected with 77Br-bromospiperone and scanned using single photon emission tomography after 16 h. Although a statistically significant increase in patients by comparison with controls could be demonstrated, wide variations in specific activity of the ligand preclude a firm conclusion. In two patients but no controls an asymmetry in striatal uptake was noted, the uptake on the left being less than that on the right.