Background Acute appendicitis is the most common cause of an acute abdomen in young adult with a life time risk of about 6% and appendectomy is the most frequently performed urgent abdominal operation. Diagnosis of acute appendicitis is clinical, the most widely used clinical scoring system is the Alvarado score also known by the acronym mantrels. A decision to operate depending on clinical suspicion only lead to removal of a normal appendix in 15- 30 % of cases Objectives To Measure the diagnostic accuracy of Alvarado score as rule in score at cut point of 7 and Assessment of the rule of application of the score in reduction of negative appendectomy. Methods This study is designed as descriptive cross sectional and includes 84 patients whom are admitted as a case of acute appendicitis by surgical emergency unit, Alvarado score was calculated for each patient. Data is analysed using SPSS. Results Negative appendectomy was found in 7.1% of patients, all were Alvarado score below 7. 37% of overall patients had complicated appendix. At cut point 3 of the score no inflamed appendix was found and at cut of point 7 no normal appendix was found. Elevated temperature was found negative in 43.6% of positively inflamed appendix. Conclusion and recommendations At cut point of 7 Diagnostic accuracy of Alvarado score is 100% (all patients at or above 7 have positive surgical appendicitis). 43% of those with positive appendicitis have no fever. Health education is required to improve and ensure early detection of appendicitis and decrease the high percentage of complicated appendix. Application of Alvarado score may decrease negative appendectomy. Alvarado score require revision and modification to include only high sensitive and specific clinical symptoms and signs and also it includes left shift of Neutrophil maturation, which is not routinely done in many laboratories.