Objective: The purpose of this study is to assess preoperative patient attributes as risk factors for unplanned intubation after primary total knee and total hip arthroplasty. Methods: This was a retrospective analysis of data collected from the National Surgical Quality Improvement Program (NSQIP) database. Patients undergoing Total Hip Arthroplasty (THA) or Total Knee Arthroplasty (TKA) who experienced postoperative intubation were included in the study. A multivariate regression was used to assess preoperative characteristics as risk factors for postoperative intubation. Results: Multivariate regression determined that perioperative transfusion of packed RBC's, cardiac comorbidities, patients older than 73, dyspnea with moderate exertion, dyspnea while at rest, diabetes mellitus requiring medical therapy, pulmonary comorbidities, current dialysis usage, body mass index greater than 29.9, and current smoker within the last year were variables associated with an increased risk of unplanned intubation after THA. Additionally, multivariate regression determined that anemia, perioperative transfusion of packed RBC's, cardiac comorbidities, patients older than 73, dyspnea with moderate exertion, diabetes mellitus requiring medical therapy, pulmonary comorbidities, and current dialysis usage were associated with unplanned intubation after TKA. Conclusion: This study identifies numerous risk factors for intubation after THA or TKA.