We analyzed the expression of a presynaptic protein, synapsin III, in individuals with schizophrenia. Since levels of synapsin III were previously found to be significantly reduced in the hippocampus of individuals with schizophrenia, we examined another brain region believed to be a major locus of dysfunction in schizophrenia, the dorsolateral prefrontal cortex (DLPFC). Western blot analyses using tissue obtained from the Stanley Foundation Neuropathology Consortium revealed that synapsin III levels were significantly decreased in the DLPFC of individuals with schizophrenia compared to controls. These findings are consistent with growing evidence of presynaptic abnormalities and prefrontal cortical dysfunction in schizophrenia.