Using the established piglet model, renal scars were produced by a combination of vesicoureteric reflux and urinary infection. The presence and extent of scarring, as determined by postmortem examination, was compared with that detected by technetium 99m dimercaptosuccinic acid (DMSA) scans performed before sacrifice. Sixty female piglets (62 refluxing units) were studied. Overall the sensitivity (true-positive/(true-positive + false-negative)) of DMSA scanning in detecting macroscopic scarring was 85% and the specificity (true-negative/(true-negative + false-positive)) was 97%. There were five false-negatives, four of which were in kidneys with minor scarring and one in which there was major scarring. There were three false-positives. We conclude that DMSA scanning has a high specificity and sensitivity in detecting renal scars in female piglets, and suggest it is the preferred method for detecting renal scars in clinical practice.