Abstract          Acute appendicitis is one of the most common surgical emergencies around the world with a life time prevalence of approximately one in seven. It's incidence is 1.5-1.9/1000 in male and female population. Scoring systems are valuable and valid instruments for discriminating between acute appendicitis and nonspecific pain abdomen. Alvarado scoring is one of them and is purely based on history, clinical examination and few laboratory tests and is very easy to apply. Advent of cross sectional computer based imaging modalities (USG, CT and MRI) in early eighties opened up new methods for diagnosis of acute appendicitis. It was also found that ultrasound was able to establish alternative diagnosis in up to one-third cases of right iliac pain like ureteric colic and gynaecological disorders. Statistical analysis of data in our study gave sensitivity of Alvarado score as 94.9%, specificity 61.9%, positive 90.3% and negative predictive value 76.4% while sensitivity of ultrasonography was 91.9%, specificity 85%, positive 95% and negative predictive value 77.2%.When both modalities were positive for acute appendicitis, no false positive result obtained. So it is concluded that the combination of Alvarado score and ultrasonography increases the sensitivity and specificity for the diagnosis of acute appendicitis.