A prospective study was performed including 40 patients with an acute abdominal syndrome presenting difficulties in defining the etiology. All patients underwent an emergency computed tomographic (CT) scan. The CT scan made the syndrome's diagnosis in 95% of cases and it permitted the detection of a lesion in 57.5% of cases. The diagnostic impact of CT scan was significant (p less than 0.01). The value and the specific contribution of CT in various diseases were analyzed. CT allowed appropriate therapeutic decisions in 95% of cases where clinical examination performance was positive in only 60% of cases. We had two negative CT results leading to an inappropriate therapeutic decision; it consisted of two cases of undiagnosed appendicitis. CT modified the primary therapeutic strategy in 30% of cases and avoided seven laparotomies.