IMPORTANCE Patients with diabetic macular edema (DME) are at high risk of vascular complications, including stroke and myocardial infarction (MI). Concerns have been raised that intravitreal dosing of vascular endothelial growth factor inhibitors in DME could be associated with an increase in cardiovascular and cerebrovascular adverse events. OBJECTIVE To evaluate the cardiovascular and cerebrovascular safety of ranibizumab, 0.5 mg and 0.3 mg, compared with sham with and without laser in DME. DATA SOURCES Patient-level data from 6 randomized, double-masked, sham-and laser-controlled clinical trials. STUDY SELECTION Company-sponsored (Genentech or Novartis) studies in DME completed as of December 31, 2013. DATA EXTRACTION AND SYNTHESIS Pairwise comparisons (ranibizumab, 0.5 mg, vs sham and laser; ranibizumab, 0.3 mg, vs sham) were performed using Cox proportional hazard regression (hazard ratios, 95% CIs) and rates per 100 person-years. Data analysis was conducted from June 1 to July 15, 2015. MAIN OUTCOMES AND MEASURES Standardized Medical Dictionary for Regulatory Activities queries and extended searches were prospectively defined to identify relevant safety end points, including arterial thromboembolic events, MI, stroke or transient ischemic attack, vascular deaths, and major vascular events as defined by the Antiplatelet Trialists' Collaboration (APTC). RESULTS Overall, 936 patients were treated with ranibizumab, 0.5 mg; 250 patients with ranibizumab, 0.3 mg; and 581 patients with sham/laser. The hazard ratios associated with all pairwise comparisons included 1 for all key cardiovascular and cerebrovascular safety end points. For ranibizumab, 0.5 mg, vs sham/laser and ranibizumab, 0.3 mg, vs sham, the hazard ratios were, respectively, arterial thromboembolic events, 1.05 (95% CI, 0.66-1.68) and 0.78 (95% CI, 0.43-1.40); MI, 0.84 (95% CI, 0.41-1.72) and 0.94 (95% CI, 0.43-2.06); stroke or transient ischemic attack, 0.94 (95% CI, 0.44-1.99) and 0.53 (95% CI, 0.19-1.42); stroke (excluding transient ischemic attack), 1.63 (95% CI, 0.65-4.07) and 0.59 (95% CI, 0.14-2.46); vascular death, 2.17 (95% CI, 0.57-8.29) and 2.51 (95% CI, 0.49-12.94); and APTC-defined events, 1.09 (95% CI, 0.63-1.88) and 1.00 (95% CI, 0.51-1.96). CONCLUSIONS AND RELEVANCE This pooled analysis includes 1 of the largest patient-level data sets on treatment of DME with ranibizumab. Although still underpowered to detect small differences for infrequent events, such as stroke, the findings suggest that intravitreous ranibizumab does not increase the risk of systemic vascular events. However, uncertainty remains for patients with DME who are at high risk for vascular disease and were not included in these trials.