Background and Purpose: In ischemic stroke, inflammatory status may condition the development of collateral circulation. Here we assessed the relationship between systemic inflammatory biomarkers and collateral status in large vessel occlusion before mechanical thrombectomy. Methods: HIBISCUS-STROKE is a cohort study including acute ischemic stroke patients with large vessel occlusion treated with mechanical thrombectomy following admission magnetic resonance imaging. MMP-9 (matrix metalloproteinase-9) and MCP-1 (monocyte chemoattractant protein-1) were measured on blood sampling collected at admission. Collateral status was assessed on pretreatment Digital subtraction angiography and categorized into poor (Higashida score, 0–2) and good (Higashida score, 3–4). A multiple logistic regression model was performed to detect independent markers of good collateral status. Results: One hundred and twenty-two patients were included, of them 71 patients (58.2%) had a good collateral status. In univariate analysis, low MMP-9 levels ( P =0.01), high MCP-1 levels ( P <0.01), a low National Institute of Health Stroke Score ( P =0.046), a high diastolic blood pressure ( P =0.049), the absence of tandem occlusion ( P =0.046), a high Alberta Stroke Program Early CT Score ( P <0.01) and a low volume on the diffusion-weighted imaging ( P <0.01) were associated with good collateral status. Following multivariate analysis, low MMP-9 levels ( P =0.02) and high MCP-1 levels ( P <0.01) remained associated with good collateral status. Conclusions: Low MMP-9 and high MCP-1 levels were associated with good pretreatment collateral status in patients with acute ischemic stroke with large vessel occlusion. These results might suggest a relationship between collateral status and inflammation.