The authors presents the results of application of ultrasound investigation, diagnostic laparoscopy and multi-helical computer tomography in diagnostics of acute appendicitis. The research was applied on 139 patients whom clinical diagnosis was hard to establish using clinical - laboratory criteria. Ultrasound signs of acute appendicitis were revealed in 44 patients out of 139 (31,6%). Diagnostic laparoscopy was performed in 37 (26,6%) patients. According to the results of laparoscopy, the diagnosis of acute appendicitis was сonfirmed in 22 (70,2%) cases. The application of CT allowed the authors to confirm or reject the supposed diagnosis in 90,8% patients. The authors came to conclusion that this non-invasive method facilitated to diagnostics of vermiform appendix inflammation and had a high diagnostic accuracy.