Objective: To explore the relationship between platelet/lymphocyte ratio (PLR), C-reactive protein (CRP), homocysteine (Hcy) and secondary cerebral infarction (CI) in patients with transient ischemic attack (TIA). Methods: Totally 62 patients with TIA in the hospital from October 2022 to October 2024 were retrospectively selected as research subjects. According to whether secondary CI occurred within 90 days after TIA, they were divided into simple TIA group (n=33) and secondary CI group (n= 29). The clinical data and blood PLR, CRP and Hcy were compared between the two groups. ROC curve was used to analyze the value of blood PLR, CRP and Hcy levels on predicting secondary CI in patients with TIA. Results: The ABCD2 score, proportion of symptom duration≥1h and proportion of TIA occurrence≥3 times in secondary CI group were significantly higher than those in simple TIA group (P<0.05). There were no statistical differences in age, gender, past history and time from onset to admission between groups (P>0.05). The levels of blood PLR, CRP and Hcy were significantly higher in secondary CI group than those in simple TIA group (P<0.05). ROC curve revealed that the AUCs of blood PLR, CRP and Hcy levels in predicting secondary CI in TIA patients were 0.793, 0.733 and 0.708 (all P<0.05). The AUC of combined prediction of the three levels was 0.868 (P<0.05), and the combined prediction value was higher. Conclusion: The levels of blood PLR, CRP and Hcy in patients with TIA can predict the occurrence of secondary CI, and combined detection has higher value.