Neurocognitive deficits are recognized as a cardinal feature of schizophrenia. Atypical antipsychotics have high affinity for many neurotransmitter receptors. Among these receptors, antipsychotics are antagonists of adrenoceptors, and this pharmacological property has been postulated to be involved in the mechanism of action of antipsychotics. We tested the hypotheses that clinical response and cognitive improvement to antipsychotic treatment are associated with genetic variation in adrenergic alpha2C receptor (ADRA2C). Fifty-seven patients with chronic schizophrenia were prospectively assessed for clinical response to antipsychotic treatment. They were subsequently genotyped for a 21 bp insertion/deletion that we identified in the 3' untranslated region (3'UTR) of ADRA2C. With regard to clinical response and cognitive improvement to antipsychotics, there was no significant association observed for this polymorphism. Our results suggest that the novel polymorphism may not play a major role in antipsychotic response.