Objective: To evaluate the efficacy and complications of mini-percutaneous nephrolithotomy (PCNL) sur-gery using 14-20 Fr access sheaths in pediatric patients, as well as the results of postoperative stone analysis and metabolic urine analysis.Material and methods: We retrospectively evaluated the records of 206 pediatric patients (232 kidney units) who underwent mini-PCNL for kidney stones in our clinic between February 2011 and December 2018. We evaluated the demographic characteristics, complications, stone-free rates, and the results of chemical analysis and urinary metabolic analysis.Results: The age ranged from 9 months to 16 years. The mean age was 5.1±3.9 years, and the median age was 3.5 years. The median stone burden was 200 mm2 (min: 100; max: 1600). Kidney stones were most commonly located in the pelvis in 118 (50.9%) patients, followed by lower calyceal stones in 42 (18.1%) and multiple calyceal stones in 38 (16.4%) patients, respectively. While the success of mini-PCNL was 80.6% after the first session, this rate increased to 87.9% after auxiliary treatments. The total complication rate was 12.9% according to modified Clavien classification. A postoperative stone analysis showed that calcium oxalate had the highest frequency with 61.1% of patients, followed by cystine stone with 21.3% of patients. Metabolic urine analysis revealed no abnormalities in 42.8% of patients. The most common metabolic ab-normality was hyperoxaluria (32%), followed by hypercalcuria (19.6%).Conclusion: Mini-PCNL is a safe and effective procedure with reasonable complications for the treatment of pediatric kidney stones. All kinds of multidisciplinary efforts are required to remove kidney stones com-pletely in pediatric patients.