One hundred and eleven male patients with alcohol dependence and 123 nonalcoholic healthy men were tested for the genetic polymorphisms of alcohol dehydrogenase 2 (ADH2), aldehyde dehydrogenase 2 (ALDH2), serotonin transporter (5-HTT) and dopamine transporter (DAT1). There were significant differences in genotype frequencies of ADH2 C992G and A13543G SNPs between alcoholic patients with family history of alcohol dependence (familial) and alcoholic patients without family history (non-familial). Genotype and allele frequencies of ALDH2 G1951A SNP in familial or non-familial alcoholic patients differ from normal controls. Neither 5-HTTLPR L/S nor DAT1 G2319A SNP genotypes nor alleles discriminated alcoholic patients from normal controls. These findings suggest that the genetic characteristics of alcohol metabolism in non-familial alcoholics fall between non-alcoholism and familial alcoholics.