Summary1Drip infusion pyelography provides more satisfactory nephrograms and pyelograms than the conventional intravenous urogram examination.2It is particularly valuable in renal insufficiency or where it is expected that the conventional examination would be of poor quality.3It is useful for determining the presence or absence of a space‐occupying lesion where there is doubt.4It may determine the nature of the space‐occupying lesion, although selective renal arteriography is considered superior in this regard.5The examination appears to be safe, although an unexplained rise in blood urea occurred in two patients and more experience in the method will be needed to assess its safety.6Reasons are given for using diluted contrast media, although it is probable that dilution of the contrast medium does not enhance the examinat