The article deals with the experience in the treatment of 3,368 patients with acute appendicitis from 1979 to 1989. Among them were 2,398 adults and 976 children. Complications developed in 190 (5.6%) patients, 5 (0.15%) patients died. The mortality rate among children was 0.3%. Complications and deaths were connected with neglected forms of the disease. 695 (20.6%) patients were admitted later than 24 hours after the onset of the disease. The patients diagnosed the disease themselves and resorted to self-treatment. Health education measures were poorly effective; it is suggested that this work should be started from early childhood. A permanently functioning seminar on acute surgical diseases was organized at the institution for doctors not practicing in surgery, but diagnostic errors were made at the prehospital stage in 117 cases by district therapists, pediatricians, and the staff of emergency aid teams. There were also cases in which operation was undertaken late after admission to the hospital and cases of hyperdiagnosis. The late-term results were studied in 109 patients without morphological changes in the removed vermiform processes, in 51.4% of them other diseases were encountered in the long-term period.