Background:Acute appendicitis is one of the most commonly diagnosed surgical diseases that its accurate diagnosis is still a problem, and there is no certainty. Ultrasound is recommended for diagnosis of appendicitis as an easy and noninvasive method. Therefore, due to the spread of disease and the urgent need to accurately diagnose in all educational centers, we decided to determine the diagnostic value of this inclusive method in identifying acute appendicitis.Materials and Methods:This is a descriptive cross-sectional research that was conducted on 540 patients referring to Educational Center of Ayatollah Kashani Hospital. All individuals suspected to appendicitis, and undergone ultrasound was included in the study, and then the result of ultrasound was compared to the obvious pathological results. Data were entered into statistical software of SPSS 20 and were analyzed.Results:According to the ultrasound findings, appendicitis was diagnosed as negative in 351 ones and positive in 189 ones. Ultrasound sensitivity in the diagnosis of appendicitis was 37.1%, while its specificity was 87.2%. The positive predictive value was 96.8% and the negative predictive value was only 11.7%.Conclusion:Considering very low-negative predictive value in educational centers, it is suggested that ultrasound is done for diagnosis of appendicitis only in complicated cases of appendicitis and differential diagnose (kidney stones, and ovarian cysts). In addition, it is recommended that routine ultrasound be avoided for all patients.