It has been more than 130 years since Reginald Fitz described for the first time the pathomorphological changes of the acute appendicitis and after the first appendectomy that was performed by H. Hancock, in the case of acute appendicitis, but the problem remains to be actual till now. Despite of the acute appendicitis is the most common abdominal emergency, there still are some compartments of this problem that need to be studied, starting with particularities of etiology of acute appendicitis and ending with particularities of clinical picture, differential diagnosis, and treatment. The article describes anatomy and physiology of the appendix. Authors presented data on history, epidemiology, etiology, pathophysiology, classifications, complications, management, treatment and prognosis of acute appendicitis. Also the article reflects characteristics of acute appendicitis in children, elderly patients and pregnancy and clinical signs depending on anatomical position of appendix. Conclusions: Earlier diagnostics and an early surgery performance in patients with acute appendicitis are the key to success, and lead to significant reduction in number of postoperative complications. We hope that our article will be useful for medical students, family doctors, and for young surgeons