The study describes the mortality (1951-1986) and morbidity (1977-1988) from appendicitis in Spain. Mortality decreased steadily throughout the study period; it was higher in men and in the elderly, both men and women. Hospital morbidity from appendicitis decreased by 40% from 1977 to 1988; this decrease was more pronounced in elderly patients; morbidity was higher in patients 15 to 24 years old. Possible causes of this evolution in morbidity are discussed.