OBJECTIVES:In children reported to the Extracorporeal Life Support Organization (ELSO) registry, to compare mortality, the need for additional cannulas, and complications associated with dual-lumen (DL) or multisite cannulation for venovenous extracorporeal membrane oxygenation (ECMO). DESIGN:Multicenter retrospective study using the ELSO registry. SETTING:Centers reporting to ELSO between January 1, 2000, and December 31, 2019. PATIENTS:Children 28 days to 18 years old supported with venovenous ECMO. INTERVENTIONS:We performed univariate and multivariable regression analyses to determine the association between venovenous ECMO cannulation strategy and in-hospital mortality, ECMO duration, and need for additional cannulas. We also compared the frequency of venovenous ECMO complications using univariate analysis. MEASUREMENTS AND MAIN RESULTS:We identified a cohort of 2034 patients, of whom 1441 (71%) were supported with DL. Support with DL, as opposed to multisite cannulation, was associated with median (interquartile range) of younger age (23 mo [6-89 mo] vs. 147 mo [64-189 mo]; p < 0.001). We failed to identify an association between in-hospital mortality and whether DL or multisite cannulation had been used (393/1441 [27%] vs. 184/593 [31%]); unadjusted and adjusted risk ratio (aRR) of death using DL as the reference group of 1.1 (95% CI, 0.7-1.9; p = 0.70). The other analyses failed to identify an association between cannulation type, ECMO duration, and the use of additional cannulas. ECMO complications were similar except for more frequent neurologic determination of death in the multisite group. CONCLUSIONS:In the 2000-2019 ELSO pediatric dataset, we failed to identify an association between venovenous ECMO cannulation type-DL or multisite-and greater aRR of ECMO outcomes.