An anesthesia follow-up program (100 000 anesthetics) and vital statistics data were used to assess the role of anesthesia in operative deaths. Four factor groups (patient, surgical, anesthesia, and "other") were assessed by logistic regression analysis to ascertain which variables were predictive of seven-day mortality. Advanced age, male gender, physical status, major surgery, emergency procedure, procedures performed in 1975 to 1979, intraoperative complications, narcotic techniques, and having one or two anesthetic drugs administered were associated with increased mortality, whereas duration of anesthesia, experience of the anesthesiologist, and inhalation techniques were not. Receiver-operator characteristic curves showed no increment in prediction of operative mortality greater than that for patient plus surgical factors when "other" or anesthetic factors were added. Patient and surgical risk factors were much more important in predicting seven-day mortality than the anesthesia factors we studied.