The incidence of appendicitis in a population of 1.07 million is estimated based on discharge rates compiled by the Central Bureau of Statistics for the years 1977 and 1978. A crude incidence rate of 140 per 100,000 inhabitants is found with a male dominance (153 v. 126). The lowest incidence rate is found in the age group 0-4, whereas the highest rates are found for patients 15-24 years of age. Seventy-four per cent of all appendicitis cases is found in the age group 5-34 years. The mean length of stay was 6.5 days, but with differences between the counties studied of up to 60%. A yearly death rate of 0.30-0.37% with a male dominance is revealed. Appendicitis cases consume only 1.2% of all hospital discharges but 11.8% of all discharges for gastrointestinal diseases. A comparison with previous studies is performed and it is suggested that most of the reported reduction in incidence rates for appendicitis most probably is caused by a more reliable data base in the recent years.