The subphrenic space, lying below the diaphragm, above the transverse colon, is divided into upper and lower compartments by the liver. On the left side, the lower compartment has two subdivisions, separated from each other by the lesser omentum, stomach, and anterior layers of the greater omentum. One of these two inferior subdivisions is located anteriorly; the other lies posteriorly and is commonly called the lesser omental bursa, the foramen of Winslow providing its only communication with the greater omental sac or peritoneal cavity. Infection followed by abscess formation may occur in any of the subdivisions of the subphrenic space, usually being secondary to inflammation elsewhere. Of a series of 3,533 subphrenic abscesses collected by Ochsner (1) 31 per cent originated in the appendix, 29 per cent in the stomach and duodenum, and 13 per cent in the liver and biliary passages; 25 per cent represented extension of thoracic lesions into the subphrenic space, and 2 per cent were secondary to trauma. In 1,531 of the cases cited above, for which details were available, more than 70 per cent of the abscesses were on the right side. Approximately 4 per cent were found in the left superior and 20.5 per cent in the left anterior-inferior space. Involvement of the left posterior-inferior space (the lesser omental sac) was relatively rare, being reported in only 3 per cent of the cases. This experience was confirmed in the series of 118 cases published by Hochberg (2), who found 12.5 per cent of the abscesses on the left side; of these, less than one-third were in the lesser omental sac. Case Report A 72-year-old while male was admitted to Multnomah County Hospital because of constant dull, aching pain in the left upper and mid-abdomen. He complained of early satiety, poor appetite, nausea, and occasional vomiting of two months duration, associated with a weight loss of approximately 15 pounds. He denied recent melena, hematemesis, constipation, and diarrhea. Five years prior to the present illness there had been an episode of hematemesis. An upper gastrointestinal series showed no abnormality at that time (Fig. 1). There were no subsequent gastrointestinal complaints and the past history was otherwise non-contributory. The patient appeared alert and co-operative, and in no acute distress. The blood pressure was 190/84; pulse rate 90, with evidence of auricular fibrillation; oral temperature 98.4° F. Heart tones were distant, and no murmurs were audible. On abdominal examination the liver edge was palpable 3 cm. below the costal margin, soft and slightly blunted. No abnormal masses were felt and there was no tenderness to palpation. The remainder of the physical examination was not remarkable. Laboratory findings were as follows: hemoglobin 14.3 gm., red blood cell count 4,800,000, white cell count 7,500 with normal differential, sedimentation rate 3/46; serology and urinalysis normal; free acid in the gastric contents.