Background: Original peritoneal equilibration test (PET) is an implementation that requires hard work for peritoneal dialysis (PD) staff. Therefore, several authors have attempted to validate short and fast PET protocols, with controversial results. The aim of this study was to evaluate the concordance between the mini-PET and original PET in children. Methods: In 26 stable continuous ambulatory PD patients, we performed an original PET with 2.27% (4 h) and a mini-PET with 3.86% glucose PD fluid (1 h) and compared ultrafiltration (UF) and small solute transports obtained with the two methods. Results: Twenty-six children, 14 males, mean age 11.4 +/- 5.6 (range 2.5-19 years), were included. Meantime on PD at time of enrollment was 35.2 +/- 24.5 months (range 6-84 months). Based on the 4-h creatinine D/P data, the number of the patients within each transport category was as follow: high, 5; average, 18; low, 3. Kappa test showed a significant concordance between original PET and mini-PET (k = 0.610). Based on the 4-h glucose D/D-0 data, the number of the patients within each transport category was as follow: high, 5; average, 17; low, 4. Kappa test showed a moderate agreement between original PET and mini-PET (0.514, p = 0.000). When Pearson correlation analysis between original PET and mini-PET was performed, there were significant positive correlations between original 2.27% PET and mini-PET (r = 0.720, p = 0.000, r = 0.638, p = 0.000, respectively). When comparing the numeric results of mini-PET and 4 h of original PET for D/C-reatinine, by simple regression analysis, we found statistically significant correlation among PETs. Conclusions: In this study, we showed concordance between the mini-PET and original PET. The 3.86% mini-PET is simple and fast methods to assess free water transport. This also gives information about total UF and small solute transports and it is in good agreement with the original PET.