Background: Inflammatory markers such as C-reactive protein and Albumin have previously been associated with poor prognosis in ST-elevation myocardial infarction (STEMI). Objective: The present study aims to investigate the relationship between the infarct-related arteries (IRA) patency and C-reactive protein/Albumin ratio (CAR) before primary percutaneous intervention (p-PCI) in patients with STEMI. Methods A total of 822 patients who underwent primary PCI (p-PCI) for acute STEMI were included in this study. Patients were divided into two groups according to IRA patency as TIMI flow 0-1 (n = 551) and TIMI flow 2-3 (n = 271). CAR ratio measured at admission was compared with IRA patency. Results: The average age of 822 patients was 55±12, and 84.3% (693) of the patients were male. The mean CAR level of the patients was determined as 0.26 (0.08-0.48). CAR level was statistically significantly higher in TIMI flow 0-1 group when compared to TIMI flow 2-3 group [0.31 (0.09-0.51) vs 0.23 (0.06-0.42); p<0.001]. In the multivariate logistic regression analysis a significant relation was found between CAR (odds ratio [OR]:1.56, 95% confidence interval [CI]:1.22-1.97, p<0.001), and neutrophil count (OR:1.72, 95% CI:1.33-2.25, p<0.001) in patients with TIMI flow 0-1 Conclusion: An inflammation-based risk index, CAR measured at admission in patients with anterior STEMI has been found to be a useful prognostic tool for predicting adverse cardiovascular outcomes. However, this finding needs to be confirmed in future prospective studies.