The prevalence of late-life schizophrenia is increasing with high burden. It is well-documented that schizophrenia affects men and women differently in terms of symptoms. Sex hormones, which play a role in the pathology and symptoms of schizophrenia, are greatly affected by aging. To the best of our knowledge, this is a study to examine the sex differences in psychiatric symptoms and their correlation with sex hormones in participants with late-life schizophrenia. Positive and Negative Syndrome Scale (PANSS) factors were evaluated. Testosterone, follicle-stimulating hormone (FSH), luteinizing hormone (LH), estradiol, progesterone, and prolactin were measured. Male participants with late-life schizophrenia had more severe negative symptoms than female participants (z = −2.56, P = 0.010), while female participants had more severe anxiety/depression compared to male participants (z = 2.64, P = 0.008). Testosterone levels in male participants were positively associated with negative symptoms (β = 0.23, t = 2.27, P = 0.025), while there was no significant association between sex hormones and symptoms in female participants. In conclusion, higher testosterone levels were associated with more severe negative symptoms in male participants with late-life schizophrenia, suggesting that attention should be paid to the sex differences in late-life schizophrenia in clinical practice.