An attempt has been made at a fuller utilization of the information content of 131I-Hippurate in four-channel renography, recording the activities over the kidneys, heart and bladder. The four-channel system was supplemented with a digital scaler, which enabled also the volume of residual urine to be determined after renography. In functional disorder of the upper outflow tract, the examinations were performed in both supine and sitting positions. The expanded procedure has rendered the familiar method of renography more valuable and has often given essential diagnostic help when used in combination with other clinical data.