Abstract Background: Acute Appendicitis (AA) remains the most frequent abdominal surgical emergency in the developed world. Failure to make an early diagnosis is a primary reason for the persistent rate of morbidity and mortality. Decision making in cases of acute appendicitis may be a problematic experience in developing countries where the facilities for investigations lack, especially in rural and semi-rural areas. Alvarado Score (AS) may be used as a guide. Aim of Study: To evaluate the effectiveness of Alvarado Score in diagnosing acute appendicitis by correlating it with the operative findings, and the pathologic findings if it is feasible. Also, to know the specificity and sensitivity of Alvarado Score as a diagnostic tool of acute appendicitis in both genders and all age groups, so we can apply it to all patients suspected to have acute appendicitis. To save time and money by diagnosing Acute Appendicitis with the help of Alvarado Score and using it as a guide in requesting a CT Abdomen for suspicious appendicitis. So, we can eventually reduce the number of negative appendices or complications of undiagnosed appendicitis. Patients and Methods: The study was conducted on 50 patients complaining of lower abdominal pain with a provi-sional diagnosis of acute appendicitis, selected non-randomly, in the Emergency Department of Harpur Memorial Hospital in Menof City, Menofeya Governorate-Egypt. Patients were assessed pre-operatively by the Alvarado scale. Post-operative histological examination of removed specimens was done. Results: The results showed that 60% of the patients were males. The mean age was 27.54, range (9-62) years old. 100% of cases had Right Lower Quadrant tenderness (RLQ) as well as Rebound tenderness, followed by; anorexia in (96%) of cases. The migration of pain to the right lower quadrant was present in (68%) of cases. Conclusion: We concluded that in our local setting, efficacy (sensitivity, specificity, and diagnostic odds ratio) of Alvarado Score, using a conventional cut off value of 7 for high-risk group, in the diagnosis of Acute Appendicitis is a good initial evaluation of patients with acute lower abdominal pain. Also, it is a cheap and quick tool to apply in Emergency Departments to rule our acute appendicitis.