© The Author(s) 2021.We investigated the relationship between the C-reactive protein (CRP) to albumin ratio (CAR) and coronary collateral circulation (CCC) in stable coronary artery disease (CAD). Patients with stable CAD (n = 354) who underwent coronary angiography for suspected CAD and had a total occlusion ≥1 major coronary artery were included in the study. The participants were divided into 2 groups according to the Rentrop score as satisfactory CCC (Rentrop 2-3) and poor CCC (Rentrop 0-1). Patients who had poor CCC had a higher CRP, neutrophil/lymphocyte ratio (NLR), and CAR levels compared with those who had satisfactory CCC (P <.001, P =.046, P <.001, respectively). The CAR (odds ratio: 3.522, 95% CI: 2.515-4.932, P <.001), CRP, NLR, and diabetes mellitus were independent predictors of poor CCC. In receiver operator characteristic curve (ROC) analysis, the optimal cutoff value of CAR to predict poor CCC was 1.27 (area under ROC curve = 0.735 [95% CI: 0.667-0.803], P <.001). A raised CAR may be an independent predictor of poor CCC.