Evaluation of the outcome of patients aged over 80 with acute abdominal complaints, who were admitted to the hospital through the emergency department. Retrospective study. City hospital, the Netherlands. 132 patients aged over 80 with acute abdominal complaints who were admitted through the emergency department in 1997. Diagnosis at admission and discharge or necropsy, diagnostic tests, treatment, morbidity, and mortality. In 27 of 132 patients (20%) the diagnosis on discharge or at necropsy differed from the initial diagnosis in the emergency department; in 18 patients (14%) an important diagnosis was missed and the severity was underestimated. Within the first 24 hours, 97% (n = 128) had blood tests, 63% (n = 83) urine tests, 58% (n = 76) plain radiograph of the abdomen, 20% (n = 26) ultrasonography, and 3% (n = 4) computed tomography (CT) of the abdomen. Of all the patients admitted, 35 (27%) were operated on. The hospital mortality of the admitted patients was 17% (n = 23) and of those operated on 34% (n = 12). The mortality in the 27 misdiagnosed patients was 59% (n = 16). The morbidity among the 109 surviving patients was 22%. Mortality was high among those aged over 80 with acute abdominal complaints who were admitted through the emergency department, particularly among those who were operated on and those who were misdiagnosed. Guidelines for an earlier and more comprehensive diagnostic approach could lead to better insight into the prognosis and thereby to more adequate and better-targeted treatmen