Results of family studies show the importance of genetic factors in etiopathogenesis of schizophrenia. Susceptibility to the disease is probably due to an interaction of many genes. This association study was conducted to investigate frequencies of alleles and genotypes in a group of patients with schizophrenia and in healthy controls. We examined DRD2 gene promoter polymorphism--insertion or deletion of the cytosine in the position -141 of 5'-flanking region of this gene. No relationship between the polymorphism under study and schizophrenia has been found.