Alvarado score is an objective assessment of right lower quadrant pain. Alvarado score is based on sophisticated statistical analysis of symptoms, signs and laboratory data in acute appendicitis. The score ≥ 7 indicates high probability of acute appendicitis. Practically speaking, it is equivalent to one`s degree of clinical suspicion. Therefore this scoring system is used to reach the clinical diagnosis. It is considered that use of the scoring system to make the clinical diagnosis would allow uniformity as more than one senior surgical resident are involved in making the decision. Other studies have shown that Alvarado score has the accuracy of 88%. Graded compression ultrasonography in diagnosis of acute appendicitis has greatly improved the ability to diagnose acute appendicitis with ultrasound. Graded compression sonography plays an important role in reducing the number of negative surgical exploration for acute appendicitis. The accuracy offered by sonography should keep negative laparotomy ratio at approximately 10%.