Schizophrenia is severe psychiatric disorder which affects 1% of general population. Diagnosis of schizophrenia is based on presence of clinical symptoms but its exact pathophysiology is still unknown. However, according to extensive research the most accepted is dopamine hypothesis by which dopamine plays central role in development of schizophrenia. Dopamine pathways in brain are followed by serotonin pathway which has inhibitory effect on dopamine. Dopamine action is regulated by dopamine transporter and catechol-o-methyltranspherase, while serotonin action is regulated by serotonin transporter and monoamine-oxidase A which is also included in dopamine metabolism. Hypothesis of this research is that polymorphisms of dopamine transporter (DAT-VNTR), catechol-omethyltranspherase (COMT Val158Met), serotonin transporter (5-HTTLPR) and monoamine oxidase A (MAOA-uVNTR) might be associated with symptoms of schizophrenia. The aims of this research were: To test association of polymorphisms and genotype combinations with schizophrenia. In group of patients with schizophrenia, test association of polymorphisms with schizophrenia symptoms. To establish regression model for prediction of schizophrenia. 314 healthy volunteers and 306 patients with schizophrenia were included in this research. Healthy volunteers were included based on MINI psychiatric questioner and physical exam. Schizophrenia was diagnosed based on DSM IV standard and symptoms of schizophrenia were assessed by PANSS and Calgary scale. For detection of polymorphisms we used PCR followed by electrophoresis with exception of COMT Val158Met polymorphism for which we used PCR-RFLP method. Comparing healthy volunteers and patients with schizophrenia, the following was established: In overall sample there was statistically significant difference in distribution of DAT-VNTR polymorphisms. In female population we found statistically significant difference in distribution of COMT Val158Met polymorphism. In male population we found statistically significant distribution of MAOA-uVNTR polymorphism. In group of patients with schizophrenia we found association of COMT Val158Met polymorphism with family heritage of schizophrenia. Logistic regression model was established for predicting schizophrenia.