Eighteen patients with complications secondary to continuous ambulatory peritoneal dialysis underwent peritoneal scintigraphy utilizing Technetium-99m sulfur colloid. Patients were divided into three groups. Group 1 patients (11) had dialysate leaks leading to abdominal-wall edema, genital edema, or exit-site drainage. Scintigrams were abnormal in nine patients in this group and frequently provided localizing information that aided in the management of leaks. Group 2 patients (five) had recurrent peritonitis. Two of these patients had abnormal scintigrams. In one instance, scintigraphy detected multiple abdominal-wall hernias that may have been responsible for recurrent peritonitis, which resolved following corrective surgery. Group 3 patients (two) had inadequate ultrafiltration but no clinical evidence of a dialysate leak. Scintigrams were negative in this group, eliminating consideration of an underlying structural defect in the peritoneum. Scintigraphic imaging is possible for several hours following instillation of labeled dialysate. This capability is important, since scintigrams that were initially negative frequently became positive after several hours of ambulation. Postdrainage images were also helpful in confirming extraperitoneal leakage. This study demonstrates that peritoneal scintigraphy is a useful diagnostic tool in the management of complications of continuous ambulatory peritoneal dialysis.