In view of the many cases recently reported of difficulty encountered in the diagnosis of subphrenic abscess, resulting in delayed operative procedure, it appears desirable to stress the roentgen-ray diagnosis of this condition. Cottle1 recently reported a case of subphrenic abscess following removal of the appendix and excision of a duodenal ulcer, in which the diagnosis was disputed for three and a half months. In spite of the fact that the clinical evidence indicated a chest lesion, the roentgenologist insisted that the fluid was beneath the diaphragm. After a delay of about four months, the roentgenologist's diagnosis of subphrenic abscess was confirmed by aspiration and, later, by operation. Case 1 (Figs. 1-6) presented somewhat similar difficulties. The physical signs apparently are often misleading. In a recent paper by Douglas,2 the following interesting explanation was offered: As usually described, the physical signs found are dulness or flatness, diminished breath