Objectives Splenectomies are often performed during open Thoracoabdominal Aortic Aneurysm (TAAA) repair, as capsular tears are common and can be associated with significant bleeding. It is unknown whether splenectomies affect short or long-term outcomes after TAAA repair. Methods All open type I-IIV TAAA repairs performed from 1987- June 2015 were evaluated using a single institutional database. Primary endpoints were in-hospital death, major adverse events (MAE) and long-term survival. Secondary endpoint was hospital length of stay (LOS). All repairs performed for rupture were excluded. Univariate analysis was conducted using the Fisher’s exact test for categorical variables and the Wilcoxon rank-sum test for continuous variables. Logistic and linear multivariable regression were used for the in-hospital endpoints and survival analyses were performed with Cox Proportional Hazards modelling and Kaplan-Meier techniques. Results Six hundred forty-nine patients met study inclusion criteria. One hundred fifty (23%) of these patients had a concurrent splenectomy (CS) and six patients required an emergency splenectomy secondary to bleeding post-operatively, leaving 156 total splenectomies while in house. Perioperative mortality rate was 5.2% in the CS group and 5.2% in the non-CS group (p=1.0). MAE were experienced by 48% of splenectomy patients compared to 34% of those without splenectomy (p=.003). Multivariable analysis revealed splenectomy to not independently predict of perioperative death (AOR: 0.95, 95% CI: 0.41-2.23, p=.9). However, splenectomy was found to be independently associated with any major adverse event (MAE) (AOR: 1.78 95% CI: 1.19-2.65, p=.005). Splenectomy was also associated with a longer LOS (+5.39 days, 95% CI: 1.86-8.92, p=.003). There was a no survival difference between the cohorts in the total splenectomy cohort in the unadjusted (log-rank p=1.0) nor the adjusted analysis (splenectomy AHR: 1.02 CI: 0.78, 1.35, p=.9). Conclusions Concurrent splenectomy during open repair TAAA did not lead to increase perioperative mortality but did lead to significantly increased perioperative morbidity and longer hospital LOS. There was no difference in long-term survival outcomes when concurrent splenectomy was performed. Splenectomy during TAAA repair did not affect long-term survival.