Voiding cystourethrography (VCU) of 407 children with vesicoureteral reflux (VUR) at our hospital during 1969-1990 was reviewed and 7 cases (8 ureters) of intrarenal reflux (IRR) were found. All the children were male and had had an episode of febrile urinary infection under one year of age. One child had a left flank mass, which was later proven a urinoma. VUR was moderate (grade III) in 3 and massive (grade IV and V) in 5. VUR was estimated as primary in one child and as secondary in 6 (anterior urethral ring 2, posterior urethral valve 2, neurogenic bladder 2). IRR was localized to the upper area in 3, to the lower area in 2, and to the whole kidney in 3. Sixty percent of those with IRR in the polar areas was associated with moderate VUR, whereas all of those in the whole kidney was with massive one. Renal scarring was assessed by excretory urography (IVP) and/or 99mTc-DMSA renoscintigraphy. Seven kidneys were evaluable; polar scars in 5, dwarf with polar scar in 1 and dwarf with poor function (suspected hypodysplasia) in 1. In 4 kidneys new scar formation was observed. It was noted, however, that IRR did not necessarily accompany renal scars of the corresponding areas and IRR to the whole kidney did not always lead to multiple scars in the whole kidney. The nature and problems of IRR, renal scars and 99mTc-DMSA renoscintigraphy were discussed. It was suggested that urinary infection played a greater part in renal scar formation.