BACKGROUND AND PURPOSE: In vitro and nonhuman in vivo studies demonstrating impaired fibrinolysis of thrombus by thrombolytic agents in the presence of iodinated contrast media (ICM) have prompted concern regarding the clinical use of ICM. A systematic review and meta-analysis were performed to investigate the proportion of patients with acute stroke experiencing recanalization after thrombolytic therapy in whom ICM were administered compared with those in whom they were not. MATERIALS AND METHODS: Embase and Medline searches identified studies reporting recanalization rates in acute ischemic anterior circulation stroke. Pooled proportions of patients who recanalized were calculated with a random-effects model, and studies involving contrast (CS) were compared with those without (NCS). RESULTS: Six studies were found in which ICM were administered, and 1 2 studies, in which they were not. Studies were statistically heterogeneous. Combined pooled proportions and 95% confidence intervals (CI) for recanalization in unselected CS and NCS were 53% (36%-70%) and 61% (52%-71%), respectively. In a subgroup analysis in which only middle cerebral artery occlusions were considered, the pooled proportions in CS (n = 3 studies) and NCS (n = 9 studies) were 66% (95% Cl, 49%-82%; I-2, 0%) and 63% (CI, 52%-74%; I-2, 82.5%). CONCLUSIONS: Recanalization rates were not significantly different inpatients who received iodinated contrast agents in clinical studies. A randomized trial to test whether ICM affect recanalization would require a prohibitively large number of subjects.