Computed tomography (CT) of the abdomen and pelvis was performed in 26 instances of suspected mass in 24 infants and children. The information obtained was compared to that of standard abdominal radiography and excretory urography (IVP). Results were analyzed prospectively. CT was able to detect and define masses more precisely than abdominal radiography and IVP. The information obtained by CT, in a single noninvasive examination emitting minimal ionising radiation, seems comparable to that offered by a combination of multiple radiological and other imaging procedures. It is conceivable that with accumulating experience and further technological improvement CT may become an excellent screening procedure in the investigation of abdominal and pelvic masses. The high cost of CT scanning may be offset by the benefits cited.