Routine DMSA scintigraphy, ultrasound (US) of the kidney, intravenous pyelography (IVP) and voiding cystoureterography (VCU) were performed in 27 consecutive adult women with recurrent acute pyelonephritis (APN) during a 12-month follow-up. Both planar and single photon emission computed tomography (SPECT) images were obtained for DMSA scan. DMSA scans were repeated in those patients with abnormal initial scan. DMSA-SPECT showed normal findings in 2, single renal cortical detect (RCD) in 9 and multiple RCD in 16 (including nonvisualization in 2). Of the 11 kidneys with normal findings or single RCD on DMSA-SPECT, only 1 (9%) showed vesicoureteral reflux (VUR) on VCU (grade I). A large proportion of those with multiple RCDs showed abnormal findings on IVP (44%, 7/16), US (38%, 6/16) or VCU (31%, 5/16); 63% in any of these three studies. 5 of 6 patients with VUR had multiple RCDs on DMSA-SPECT, and 3 of these 5 showed no abnormality on IVP or US. 7 patients who needed other managements besides initial standard antibiotic treatment had multiple RCDs on DMSA-SPECT. 15 normal women were also studied and showed normal DMSA-SPECT, US and IVP, in all cases. Follow-up DMSA-SPECT was done in 16 patients (7 with single RCD, 9 with multiple RCD). All 7 patients with single RCD showed improvement, in those with multiple RCDs improvement was observed in 2, no change in 7 on follow-up studies. We conclude: (1) DMSA-SPECT is a useful initial diagnostic tool in adult women with recurrent APN to identify patients who need more extensive radiological studies. (2) The multiple RCDs on DMSA-SPECT indicate irreversible tissue damage in most adult women with recurrent APN.