Plain films of the abdomen, ultrasonography, and computed tomography were performed on 180 patients to rule out an intraabdominal abscess. The efficacy of the different modalities was reviewed in retrospect. Thirty-six of these 180 patients had a definite abscess formation. This was demonstrated in 65% of the plain film examinations, in 44% by ultrasonography, and in 94% by computerized tomography. Computed tomography seems efficient in ruling out abdominal abscess.