From 1955 to 1979, in Rochester, Minn, 193 residents with a mean age of 46 years underwent splenectomy. Only two cases of fulminant sepsis were documented during the 1,090 person-years of follow-up (0.18 cases per 100 person-years) in this unselected population. The incidence of any type of serious infection subsequent to splenectomy was estimated at 7.16 infections per 100 persons-years of follow-up (78 cases). The incidence of infections was significantly increased among patients undergoing incidental splenectomy in conjunction with abdominal operations for malignant neoplasms or other conditions. Immunosuppression, radiation, and chemotherapy also significantly increased the risk of subsequent infection. The low risk of fulminant sepsis after splenectomy in the general adult population justifies a policy of individualization of each case as to the relative merits of splenectomy v splenic preservation.