Background: Acute appendicitis is one of the most common acute abdomen presentation. Clinical and laboratory findings are the mainstay of diagnosis of acute appendicitis..But the clinical diagnosis is not always straightforward, specially in patients who have atypical clinical presentation.Delay in diagnosis result in complications and false positive diagnosis also leads to unnecessary negative appendectomy. Ultrasound is said to be the mainstay imaging modality to diagnose appendicitis. Objective: The objective of the study was to assess the agreement of ultrasound and intraoperative findings in the diagnosis of acute appendicitis and its associated factors Methods and materials: Institutional based cross sectional study was conducted.The study was conducted from September 2021 to November 2021G.C.The sample size was 337,and all patients who were clinically suspected of acute appendicitis and send to Radiology department for ultrasound scanning were included. Results: There is very good (strong) agreement between ultrasound finding and intraoperative finding with Kappa value of 0.822(95%CI).The sensitivity, specificity and accuracy of ultrasound in the diagnosis of acute appendicitis is 96.7%, 94.1% and 96.4% respectively with positive predictive value of 99.3% and negative predictive value of 76.2%. Gender and qualification of personnel who has done ultrasound are significant predictors of agreement of ultrasound and intraoperative findings of acute appendicitis Mesenteric lymphadenitis, renal stone, PID, ectopic pregnancy and other miscellaneous disease are the alternative diagnosis by ultrasound in decreasing order. Key Words: Acute appendicitis,ultrasound,appendectomy, sensitivity, specificity