Background: Although the appendix is the most commonly resected and examined intra-abdominal organ, the pathogenesis and etiology of acute nonspecific appendicitis remain enigmatic. This retrospective study aimed to assess the prevalence of parasitic infection in surgically removed appendices and to evaluate the probable associations between the presence of parasites and the occurrence of appendicitis through parasitological and histopathological examinations of the appendectomy specimens. Materials and methods: This retrospective study was carried out from April 2016 to March 2021 among all patients referred to hospitals affiliated with Shiraz University of Medical Sciences, Fars Province, Iran, for appendectomy. Patient information, including age, sex, year of appendectomy, and type of appendicitis, was collected from the available data in the hospital information system database. In positive cases, all pathology reports were retrospectively evaluated for the presence of the parasite and its type, and analytical and descriptive statistics were carried out using SPSS software version 22. Results: A total of 7628 appendectomy materials were evaluated in the present study. Of the total participants, 4528 (59.4%, 95% CI: 58.2–60.5) were males, and 3100 (40.6%, 95% CI: 39.5–41.8) were females. The mean age of participants was 23.87±14.28 years. Overall, Enterobius vermicularis was observed in 20 appendectomy specimens. Fourteen of these patients (70%) were less than 20 years old. Conclusion: This study indicated that E. vermicularis is one of the common infectious agents that could be found in the appendix and may increase the risk of appendicitis. Therefore, in terms of appendicitis, clinicians, and pathologists must be aware of the possible presence of parasitic agents, especially E. vermicularis, to treat and manage the patients sufficiently.