To identify altered mRNA expression of regulator of G-protein signalling 4 (RGS4) in the superior temporal gyrus (STG) in schizophrenia mRNA expression of RGS4 was measured from post-mortem STG tissue from 13 individuals with schizophrenia and 13 matched non-psychiatric controls using relative real-time PCR. Significantly decreased expression of RGS4 mRNA in the STG in schizophrenia was identified in 10 of the 13 matched pairs. Altered expression of RGS4 in cortical regions previously implicated in schizophrenia, such as the STG further supports the notion of RGS4 as a potential genetic and functional biological marker of schizophrenia.