Female Sprague-Dawley rats were administered continuous haloperidol or no drug for 32 weeks via subcutaneous silastic implants. Three days after drug withdrawal, animals were rapidly decapitated and tissue samples were analyzed for levels of G alpha subunits for Gi and Gs using immunoblotting procedures. No significant differences were seen between groups in the dopaminergic terminal regions of the medial prefrontal cortex, nucleus accumbens, or dorsolateral caudate-putamen. These results suggest that haloperidol administered in a regimen known to produce alterations in several parameters of dopamine function fails to alter the amount of receptor-linked G protein subunits in rat brain.