Objective: To investigate the relationship between systemic immune in ammation index (SII), C-reactive protein/albumin ratio (CAR), lymphocyte/CRP ratio (LCR), and apical thrombus development. Study Design: Observational, cross-sectional study. Place and Duration of the Study: Bursa City Hospital, Turkey, from 1st January to 31st March 2023. Methodology: Twenty-two patients with a clinical presentation of acute anterior myocardial infarction and diagnosed with LVAT during follow-up were included. Sixty-eight patients with acute anterior myocardial infarction (AMI) were selected as the control group (comparison). Clinical and demographic characteristics, laboratory data, echocardiographic ndings, coronary angiography, and percutaneous coronary intervention data were recorded. SII was calculated by the formula Neutrophil (N) × Platelet (P) / Lymphocyte (L). CAR and LCR values were also determined. Results: While there was no signi cant di erence between the two groups in terms of SII, CAR was signi cantly higher and LCR was signi cantly lower in the apical thrombus group. The cut-o value for CAR was 0.165 (sensitivity=63.64%, speci city=74.60%, AUC=0.718; p <0.05). For LCR, the AUC value of 0.382 and below was found to indicate the presence of apical thrombus with a probability of 69.8% (sensitivity=68.18%, speci city=67.16%, p= 0.002). Conclusion: No signi cant relationship was found between SII and apical thrombus in the detection of LVAT, whereas high CAR and low LCR were associated with the presence of apical thrombus.