Background: Current UK National Health Service (NHS) guidelines recommend appendicectomy as gold standard treatment for acute uncomplicated appendicitis. However, an alternative non-surgical management involves administrating antibiotic-only therapy with significantly lower costs. Therefore, a UK-based cost-utility analysis (CUA) was performed to compare ap-pendicectomy with an antibiotic-only treatment from an NHS perspective. Methods: This eco-nomic evaluation modelled health-outcome data using the ACTUAA (2021) prospective multi-centre trial. The non-randomised control trial followed 318 patients given either antibiotic therapy or appendicectomy, with quality of life (QOL) assessed using the SF-12 questionnaires adminis-tered 1-year post-treatment. A CUA was conducted over a 1-year time horizon, measuring benefits in quality adjusted life years (QALYs) and costs in pound sterling using a propensity score-matched approach to control for selection based on observable factors. Results: The CUA produced an in-cremental cost-effectiveness ratio (ICER) of −GBP 23,278.51 (−EUR 27,227.80) per QALY. Therefore, for each QALY gained using antibiotic-only treatment instead of appendicectomy, an extra GBP 23,278.51 was saved. Additionally, two sensitivity analyses were conducted to account for post-operative or post-treatment complications. The antibiotic-only option remained dominant in both scenarios. Conclusion: While the results do not rely on a randomized sample, the analysis based on a 1-year follow-up suggested that antibiotics were largely more cost-effective than ap-pendicectomy and led to improved QOL outcomes for patients. The ICER value of −GBP 23,278.51 demonstrates that the NHS must give further consideration to the current gold standard treatment in acute uncomplicated appendicitis.