We investigated the human serotonin receptor, HTR2 genotype among 73 alcoholics. We found that there might not be a significant difference between alcoholics and controls in the frequency of HTR2 C1/C2 gene (MspI polymorphism). This result suggested that the HTR2 C1/C2 gene might not be associated with the risk factor for developing alcohol dependence. Further studies are required to determine whether or not a novel serotonin receptor polymorphism reflects pathogenesis of alcoholism.