The incidence of morbidity and mortality in 365 consecutive patients with a mean age of 60 years who underwent intraabdominal operation for a variety of cancers involving different organ systems over a recent 2-year period was analyzed. The primary tumor sites were the esophagus (21 patients), gastroduodenum (33 patients), liver and gallbladder (6 patients), pancreas (15 patients), colorectum (101 patients), lymphoproliferative disorders (35 patients), abdominal carcinomatosis (45 patients), genitourinary and gynecologic systems (94 patients), and other sites (15 patients). One hundred eighty-two patients (49 percent) had 1 or more complications (grouped as gastrointestinal, septic, cardiopulmonary, and nonseptic) and 47 patients died (12.9 percent). The 145 patients who underwent a palliative procedure had the highest morbidity and mortality rates (41 percent and 21 percent, respectively). In the 168 patients who had curative resection, the morbidity and mortality rates were 39 percent and 9 percent, respectively, and in 51 patients with a diagnostic laparotomy, 20 percent and 4 percent, respectively. Age was not a contributory factor. The 177 malnourished patients had a significantly higher incidence of complications (72 percent) and postoperative death (23 percent) than the well-nourished patients (29 percent and 4 percent, respectively; p less than 0.001). These differences also existed with each form of complication. Of those patients without complications, the majority resumed consuming 60 percent of their caloric requirements by postoperative day 9. In the majority of patients with complications, resumption of adequate oral intake occurred by postoperative day 20.