Introduction: There are no guidelines regarding the use of bovine pericardial or porcine valves for aortic valve replacement, and prior studies have yielded conflicting results. The current study sought to compare short- and long-term outcomes in propensity-matched cohorts of patients undergoing isolated AVR with bovine versus porcine valves. Methods: This was a retrospective study utilizing an institutional database of all isolated bioprosthetic surgical aortic valve replacements performed at our center from 2010 to 2020. Patients were stratified according to type of bioprosthetic valve (bovine pericardial or porcine), and 1:1 propensity-score matching was applied. Kaplan-Meier survival estimation and multivariable Cox regression for mortality were performed. Cumulative incidence functions were generated for all-cause readmissions and aortic valve reinterventions. Results: A total of 1,502 patients were identified, 1,090 (72.6%) of whom received a bovine prosthesis and 412 (27.4%) of whom received a porcine prosthesis. Propensity-score matching resulted in 412 risk-adjusted pairs. There were no significant differences in clinical or echocardiographic postoperative outcomes in the matched cohorts. Kaplan-Meier survival estimates were comparable, and, on multivariable Cox regression, valve type was not significantly associated with long-term mortality (HR 1.02, 95% CI: 0.74, 1.40, p=0.924). Additionally, there were no significant differences in competing-risk cumulative incidence estimates for all-cause readmissions (p=0.68) or aortic valve reinterventions (p=0.25) in the matched cohorts. Conclusion: The use of either bovine or porcine bioprosthetic aortic valves yields comparable postoperative outcomes, long-term survival, freedom from reintervention, and freedom from readmission.