Objective: Neutrophil-to-lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR), and platelet-to-lymphocyte ratio (PLR) have been used as markers of inflammation in mental illness. However, these indices have not been widely used in schizophrenia research in Chinese participants. Our aim was to use these ratios to explore the relationship between schizophrenia and inflammation. Methods: In this retrospective cross-sectional study, we collected total blood cell counts of 549 patients with schizophrenia and 930 healthy controls at Beijing Huilongguan Hospital in October 2019. We analyzed the subjects’ platelet, lymphocyte, monocyte, and neutrophil counts; compared the calculated NLR, MLR, and PLR between patients and healthy controls; and evaluated the correlations with age and gender. Results: Platelet and lymphocyte counts were significantly lower, while NLR and MLR were significantly higher, in patients with schizophrenia compared to healthy controls. Additionally, monocyte count, lymphocyte count, MLR, and NLR were different between male and female subjects. Conclusion: This study supports the inflammatory hypothesis of schizophrenia in the Chinese population.