BACKGROUND:  Acute Appendicitis is the most frequent surgical emergency encountered worldwide. This study was conducted to compare the efficacy of Tzanakis scoring and Alvardo scoring in diagnosing acute appendicitis. OBJECTIVES: Tha aim of this study is to compare the efficacy of Tzanakis score  system and Alvarado scoring system in diagnosing Acute Appendicitis. Methods: This was a prospective and non randomized observational study conducted in Government  Dharmapuri Medical college Hospital during 2015–2016. It includes 400 clinically diagnosed cases of Acute Appendicitis who underwent emergency open or Lap Appendicectomy .  Final diagnosis was based on histological findings given by Pathologist. Results: The sensitivity, Specifity, positive Predictive value and Negative Predictive value of Tzanakis score was 86.9%,75%, 97.5% and 33.3% respectively. The sensitivity, Specifity, positive Predictive value and Negative Predictive value of Alvarado score was 76%, 75%, 97.2% and 21.4% respectively. Negative Appendicectomy was 8.0% Conclusion: Tzanakis scoring system is an effective scoring system in diagnosing acute appendicitis.