Introduction: Ultrasound is widely available, easy-to-use and less expensive than most other imaging methods. It is widely used as a non-invasive method to diagnose acute appendicitis; however, its efficiency still remains questionable, especially when compared to costlier and invasive methods such as computed tomography. Methods: An exploratory review of past literatures on the usage of ultrasound technique in the diagnosis of acute appendicitis in adult patients, and the role of other imaging techniques were undertaken for the study. Results: The gold standard for the diagnosis of acute appendicitis still remains a histopathological confirmation after appendectomy. The study further shows imaging has high diagnostic accuracy in the diagnosis of acute appendicitis with low rate of negative appendectomy (<10%). Multiple reasons are identified, including the introduction of computed tomography imaging especially in those patients where ultrasound was unequivocal, more education on imaging which leads to better operator skill or improved performances of machines. Conclusion: Imaging undoubtedly plays an important role in the diagnosis of acute appendicitis with ultrasound remaining the first-line method in patients referred with clinically suspected acute appendicitis. Nevertheless, those with borderline ultrasound findings or unable to visualize appendix on ultrasound with highly suspicious sign and symptoms were offered other imaging modalities such as CT scan. Recommendation: It is recommended that the managing team balance the risk of radiation exposure, risk of delay in urgent operation and risk of perforation prior to a decision.