In-hospital mortality, length of stay (LOS), and level of postdischarge care in infected and noninfected surgical patients were studied. An analysis was conducted of a database that included diagnostic, procedure, and drug data collected when surgical patients were discharged from the hospital. Hospitals consisted of 90 nongovernment, nonspecialty, teaching, and nonteaching acute care hospitals of more than 100 beds. Patients in the database included 288,906 patients of all ages hospitalized between July and September 1994. Patients selected of those who had undergone procedures likely to pose a moderate to high risk of infection. Of the 288,906 patients, 12,384 had undergone a moderate- to high-risk procedure; of these, 1,479 (11.9%) had had an infection during their hospitalization. Infection rates ranged from 1.9% to 25.4%, depending on the procedure. The in-hospital mortality rate in infected patients was 14.5%, versus 1.8% for noninfected patients. Similarly, LOS in infected patients (median, 14 days) was substantially greater than in noninfected patients (4 days). About 24% of infected patients required additional professional care after discharge, compared with 7% of noninfected patients. Infection occurs in a substantial portion of surgical patients and is associated with a higher death rate, longer hospitalization, and more intense postdischarge care.