Objective:To asses the effects of quetiapine therapy on body mass index (BMI) and serum level of testosterone, prolactin, follicle stimulating hormone (FSH), luteinizing hormone (LH), and estradiol (E2) in newly diagnosed male schizophrenic patients in comparison to healthy controls. Patients and methods: Thirty male patients with schizophrenia were included in this study. The diagnosis of schizophrenia was made according to DSM-IV criteria of the American Psychiatric Association (APA). Another thirty apparently healthy male individuals were included in the study as a control group. Blood samples were taken initially from patients and controls and assay of serum testosterone, prolactin, FSH, LH, and E2 were done using enzyme -linked fluorescent immunoassay (ELFA) technique by vidas instrument. Later, after 6 months of quetiapine therapy, other blood samples were taken and assay of the same parameters were done. Calculation of BMI was done for the patients and controls using special equation. Results: There was an insignificant difference in the mean BMI, serum testosterone, prolactin, FSH, LH, and E2 levels between patients in the pre-therapy stage group and in both the post-therapy stage group and controls. Conclusion: Chronic quetiapine therapy might be regarded as a safe drug with regard to effects on BMI and serum levels of reproductive hormones in newly diagnosed male schizophrenic patients.