PurposeTo compare the safety and effectiveness of n-butyl cyanoacrylate (nBCA)–ethiodized oil (NE) mixture and nBCA–ethiodized oil–ethanol (NEE) mixture embolization for Type II endoleak (T2EL) after endovascular aortic repair. Materials and MethodsThis study included 32 patients with 49 procedures who underwent T2EL embolization between January 2008 and June 2022. Cases with no follow-up after embolization, technical failure, treatment with coil only, Type I endoleak at the embolization, and re-embolization were excluded. The resultant final cohort included 24 patients (14 men and 10 women; mean age, 83.3 years [interquartile range, 77–89 years]) who underwent initial T2EL embolization, with 15 patients in the NE group and 9 patients in the NEE group. The 2 groups were compared in terms of adverse events (AEs), freedom from sac enlargement, and freedom from reintervention. ResultsThe follow-up period after embolization for T2EL was 960 days (SD ± 1,007) in the NE group and 484 days (SD ± 192) in the NEE group, without significant differences. No AEs above moderate were observed in either group. The rate of freedom from sac enlargement at 1 year was 65.0% in the NE group and 87.5% in the NEE group (P = .03). The rate of freedom from reintervention at 1 year was 69.2% in the NE group and 100.0% in the NEE group (P = .02). ConclusionsThe NEE group had significantly higher rates of freedom from sac enlargement and reintervention at 1 year compared with the NE group. These results suggest that T2EL embolization with NEE may be more effective than that with NE.