Preoperative oral antacid therapy has been used effectively to reduce the number of emergency obstetric patients “at risk” of developing acid-aspiration syndrome. Thirty-three nonobstetric adult patients requiring emergency surgery were selected to determine whether the protective effects of antacid therapy could also be derived in this highrisk group. Maalox-treated patients had a mean gastric pH of 6.46 ± 0.5 and gastric volume 21.5 ± 3.6 ml, with none at risk, whereas control patients had mean pH of 3.71 ± 0.43, gastric volume 71.5 ± 16.5 ml, and 42.1% at risk. This report suggests that preoperative antacid therapy should reduce the incidence of acid aspiration and subsequent morbidity and mortality in patients requiring emergency surgery.