Background: Appendicitis is the most important acute surgical condition of the abdomen, and appendectomy constitutes one of the most common surgical operations worldwide. Many factors can cause appendicitis but the intestinal parasitic infections are one of the most important causes. Objective: The present study aimed to evaluate and detect the role and incidence of various parasitic infections in appendectomy specimens from Egyptian adult patients with acute appendicitis attending the General Surgery Emergency room at Al-Azhar University Hospitals, Cairo, Egypt (Al-Hussein and Sayed Galal Hospitals). Patients and methods:  The present study was carried out on 200 patients undergoing appendectomy with a provisional diagnosis of acute appendicitis during the period from   December 2015 to November 2016. The removed appendices were fixed in 10% buffered formalin, sectioned, stained with H&E and examined for histopathological changes and presence of parasites. Stool examination was also done by direct smear, formol ether concentration techniques as well as CBC examination for all patients. Results: Stool examination revealed 120 (60%) out of the total 200 appendectomy patients were positive for parasitic infections, while CBC examination revealed leucocytosis among 167 (83.5%), and eosinophilia in 40 (20%) as well as anemia in 43 (21.5%) in all the studied patients. Histopathological examination revealed parasitic infections in 6 (3%) of appendectomy specimens. The presence of E. vermicularis worms and their eggs as well as Schistosoma ovawere observed in 4 (2%) and 2 (1%) of cases respectively. Features of acute suppurative appendicitis were observed in 143 (71.5%) of cases, of which, 98(49%) cases had luminal obstruction by fecalith and 45 (22.5%) showed patent lumen. Non suppurative appendicitis were presented in 57 cases (28.5%) which included lymphoid hyperplasia in 21 cases (10.5%) and neuronal hyperplasia in 6 cases (3%) as well as granulomatous appendicitis with features consistent with appendiceal Crohn's disease (CD) in 30 cases (15%). Conclusion: The study concluded that parasitic infections constitute 3% of the surgically removed appendices where Schistosoma eggs and E. vermicularis (adults and eggs) were the parasites recorded. So differential diagnosis of parasitic infections in the etiology of acute appendicitis should be made properly which can save patients from a negative laparotomy, morbidity and even mortality.