Difficulties in diagnosis especially arise in very young, elderly patients and females of reproductive age because they are more likely to have an atypical presentation, and many other conditions may mimic acute appendicitis in these patients. Many surgeons advocate early surgical intervention for the treatment of acute appendicitis to avoid perforation accepting a negative appendectomy rate of about 15- 20%. Removing normal appendix is an economic burden on both patients and health resources. Misdiagnosis and delay in surgery can lead to complications like perforation and finally peritonitis. Patients were either subjected to emergency laparotomy at the time of admission or after few hours of conservative management. Emergency appendicectomy was done by open method under spinal or general anesthesia in all cases. Final diagnosis to be confirmed by Histopathological Examination of the specimen by the pathologist. Data was analyzed to compare the efficacy of both scoring systems in diagnosing Acute appendicitis. The sensitivity & specificity of Modified Alvarado Score was 95.81% & 94.11% with a positive predictive value of 98.75% & negative predictive value of 80%. The positive likely hood ratio was 16.18 and negative likelihood ratio was 0.05. The sensitivity and specificity of Tzanakis score was 97.59% and 94.11% respectively y with a positive predictive value of 98.78% and negative predictive value of 88.88%. The positive likely hood ratio was 16.59 and negative likelihood ratio was 0.03.