In a previous report from this institution, 21% of splenectomies performed between 1957 and 1967 were for iatrogenic injury to the spleen. In the present study, encompassing the years 1971 to 1987, the frequency of iatrogenic splenic injury was reduced to 9% (134 of 1,557 splenectomies). However, there has been no evidence of a progressive decrease in accidental splenic injury from 1971 to 1987. Although the number of injuries related to operations on the stomach or repair of hiatus hernia have declined somewhat in the past decade, the incidence of splenic injuries secondary to colectomy and nephrectomy has not changed appreciably, and injuries linked to complex operations on the aorta and its branches (19 cases) have increased. No evidence could be found that morbidity was increased if the splenic injury is promptly recognized and managed by splenectomy. However, 13 of these 134 patients required reoperation for control of continued bleeding from unrecognized iatrogenic splenic trauma. Constant awareness of the continued prevalence of this operative complication and the mechanisms by which it is produced should enable surgeons to lessen its frequency and potential sequelae.