Objective: To investigate the correlations of cognitive function with serum levels of homocysteine (Hcy), sex hormone binding globulin (SHBG), and leptin in patients with schizophrenia. Methods: This was retrospective study. This study included 58 patients with schizophrenia (SCZ) as observation group and 60 clinically healthy individuals as control group admitted to Xiangshan County Hospital of Traditional Chinese Medicine Medical and Health Group Third Hospital from March 2022 to June 2023. Serum levels of Hcy, SHBG, and leptin in the two groups were measured, and Pearson correlation analysis was conducted to investigate the correlations between the Hcy, SHBG, and leptin levels and the psychiatric symptoms and cognitive function in the observation group. Results: The Hcy and SHBG levels in the observation group were significantly higher than those in the control group (p<0.05, respectively), and the leptin level was lower than that in the control group (p<0.05). The observation group scored significantly lower than the control group for each dimension of the MCCB (p<0.05, respectively). In the observation group, Hcy was positively correlated with negative symptoms and the PANSS total score (p<0.05, respectively) and was negatively correlated with scores for the leptin was negatively correlated with negative symptoms and the PANSS total score (p<0.05, respectively) and was positively correlated with scores for speed of processing (SOP), WMS-III, BVMT, and MSCEIT (p<0.05, respectively). Conclusions: Increased levels of Hcy and SHBG and decreased leptin are strongly associated with the occurrence of cognitive impairment in SCZ cases. Therefore, clinical observation and monitoring of these markers can help identify changes in patient conditions. doi: https://doi.org/10.12669/pjms.40.10.8923 How to cite this: Xu Y, Qian X, Zhang M, Liang M. Correlations of cognitive function with serum levels of homocysteine, sex hormone binding globulin, and leptin in patients with schizophrenia. Pak J Med Sci. 2024;40(10):2319-2323. doi: https://doi.org/10.12669/pjms.40.10.8923 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.