INTRODUCTION: Anesthetic preoperative assessment is a cornerstone of safe elective surgery, particularly as we deal with an aging and increasingly comorbid population. Pre-assessment allows an opportunity to optimize patients for surgery and has the potential to uncover medical issues of which the patient was previously unaware. The purpose of the study was to explore the number of new incidental medical diagnoses uncovered during routine preoperative assessment for elective orthopaedic procedures. METHODS: A retrospective chart review was carried out of patients attending preoperative assessment at Cappagh National Orthopaedic Hospital (CNOH) between July and December of 2022. In total, 500 patients were included. Patient demographics and outcomes of preoperative assessment, including any new medical diagnosis as well as routine hemoglobin values, body mass index (BMI), and electrocardiogram (ECG) findings, were recorded in encrypted and anonymized data files. In total, following the exclusion of incomplete or duplicated records as well as non-arthroplasty cases, 482 patients were included in this study. The average age of participants was 67 years (range, 29 to 90), with 264 (54.7%) women and 218 (45.2%) men. The majority of patients were being pre-assessed for elective joint arthroplasty. RESULTS: The most common new incidental diagnoses were cardiac in nature, with 36 (7.5%) patients of the overall cohort requiring new onward referrals to a cardiology service. In total, 63, or 13% of patients, required new medical management, and 45 patients overall, or 9.3%, were deemed not fit to proceed to surgery at the initial pre-assessment with further investigations required. CONCLUSION: Preoperative anesthetic assessment plays a key role in the optimization of patients for elective orthopaedic procedures. Our study also highlights a secondary benefit of uncovering a major number of incidentally discovered new medical diagnoses, in particular cardiac. This secondarily benefits the patient by allowing for earlier detection and treatment of potentially life-threatening comorbidities.