Objectives: Schizophrenia is a complex neuropsychiatric disorder that affects approximately 1% of the population. Estrogens may play an important role in the etiology and treatment of this disorder. They mediate effect by either estrogen receptors. GPR30 is an alternative G protein-coupled receptor distinct from the classical estrogen receptors (ER alpha and ER beta). We aimed to investigate the association between GPR30 gene SNP rs3808350 and gonadal hormone (estrogen and testosterone) levels, and their association with development of schizophrenia, in a Turkish population. Methods: A total 117 schizophrenia patients and 123 control individuals were genotyped with method Real-Time PCR. Results: In the comparison of the patients and the control group with regard to the SNP genotype and allele frequencies did not show significant differences. However, there was a significant decrease in the presence of AA+AG genotypes in the patient group. There were significant differences in terms of estrogen, testosterone. In the patient group, estrogen and testosterone levels were lower than the control group. Conclusions: This is the first study examining allele and genotype frequencies of GPR30 gene SNP rs3808350 in schizophrenia patients. Because of effects of gene polymorphisms may differ in the population from the population, we may suggest that role of GPR30 gene SNP rs3808350 in development of schizophrenia must be investigated in different and wider populations.