Background: Appendiceal mucoceles, often diagnosed incidentally, present a rare challenge due to their similarity to acute appendicitis. The prognosis depends on the neoplasm's grade, and complete surgical resection is essential for favourable outcomes. This case report describes a patient with an incidental appendiceal mucocele found during surgery for suspected appendicitis. Case Presentation: A man in his 70s presented with a 1-week history of mild to moderate right iliac fossa pain. Initial imaging suggested acute appendicitis, with differential diagnoses including Meckel’s diverticulitis and ileal diverticulitis. On laparoscopy, dense adhesions and a calcified, distended appendix were noted, prompting conversion to open surgery. A right hemicolectomy was performed, and the specimen was sent for histopathological evaluation. Results: Histology confirmed a low-grade appendiceal mucinous neoplasm (LAMN) with no evidence of malignancy in the 14 lymph nodes. The surgical margins were negative, and the American Joint Committee on Cancer stage was pTis N0 R0. Postoperative recovery was uneventful, and the patient was discharged with a follow-up plan including colonoscopy in 6 months. Conclusion: This case highlights the importance of preoperative imaging in diagnosing appendiceal mucoceles and avoiding complications such as pseudomyxoma peritonei. LAMN management remains controversial, but surgical resection with clear margins offers favourable outcomes. Further studies are needed to refine treatment strategies, especially for intermediate-risk features.