Objective: Interest in the association between female sex hormones and mental diseases is not new. A possible association between schizophrenia and estrogens is remarkable. Research on the subject suggested that, women with schizophrenia have chronic gonadal hypofunction and hypoestrogenism. With regard to the hypothesis claiming; insufficient functioning of the sexual glands and estrogen deficiency in women with schizophrenia, the onset of the puberty may be later. In this study, our aim is to examine whether there is difference between women with schizophrenia and mentally healty women considering the age at menarche. Methods: In this study, we included 289 patients who were diagnosed with schizophrenia and 100 mentally healthy individuals from the outpatients. relatives in psychiatry and cardiology outpatient clinic as control group. SCID-I is used to confirm the disorder in schizophrenia group, and to exclude any mental illness in the control group. Those with mental retardation or organic brain disorders were excluded from the study. Individuals. personal information and age at menarche is determined with a sociodemographic form in consultation with the patient and a relative. Results: Compared to controls, the mean age at menarche was significantly higher in women with schizophrenia. Discussion: According to our findings, puberty is later in women with schizophrenia. This result supports the hypothesis of chronic gonadal insufficiency and hypoestrogenism in female patients with schizophrenia.