Purpose: 99mTechnetium dimercaptosuccinic acid (DMSA) scan has been used for early diagnosis of acute pyelonephritis (APN). However, the interpretations of the findings obtained have not yet been well-established. This study aimed to evaluate the relationships between DMSA findings and clinical parameters including age and fever duration. Methods: All patients diagnosed with APN and underwent DMSA scan during hospitalization were included. The positive rates for abnormal DMSA scans were analyzed according to the age of patients, fever duration prior to admission, and total fever duration. DMSA scan findings were divided into 3 categories according the characteristics of the lesions: single defect, multifocal defects on a single or both kidneys, and discrepant defects, and we compared with voiding cystourethrography (VCUG) findings according to DMSA lesions. Results: During January 2005 to December 2015, a total 320 cases fit the inclusion criteria. Of those, 141 (44.1%) had abnormal DMSA scans. The infant group (0-1 year of age) had shorter total fever duration (3.7 vs. 5.2 days, p = 0.001), and lower C-reactive protein (CRP) value (6.3 vs. 8.5 mg/dL, p = 0.001) and DMSA positive rate (38.5% vs. 60.6%, p = 0.01) compared to children group (2-15 years of age). Patients with abnormal scans showed longer total fever duration (4.4 days vs. 3.5 days, p = 0.01) and higher CRP (8.0 vs. 5.8 mg/dL, p = 0.001) compared to those with normal scans. The positivity rate of abnormal scans did not differ between the patients with short fever duration prior to admission of 2 days and those with longer fever duration of ＞3 days (47.9% vs. 40.9%, 72/176 vs. 69/144). However, patients with longer total fever duration tended to have a higher rate of abnormal DMSA scans. In cases with single defect, multifocal defects, and discrepant defects, vesicoureteral reflux was observed in 22.4% (11/49), 60% (9/15) and 70.6% (12/17), respectively. Conclusions: Although DMSA scan has limitations for early diagnosis, DMSA scan findings may aid in prospect the severity of systemic inflammation and detection of vesicoureteral reflux.