To investigate whether the combination of lower pole pelvicaliceal anatomic features in a single index can predict the outcome of shock wave lithotripsy treatment (SWL) of lower caliceal stones in children more accurately in stead of considering every single anatomic feature alone.The clinical records of children with lower caliceal stones who underwent SWL between 2002-2008 were reviewed. After excluding patients with ureteropelvic obstruction, major renal anatomic abnormalities, non-calcium stones, metabolic abnormalities, history of recurrent stone disease, multiple stones and previous renal surgery;25 paediatric patients were enrolled into study. Lower pole infundibulopelvic angle (IPA), infundibular length (IL) and width (IW) were measured from intravenous pyelography. Also, paediatric infundibulopelvic index(IPI) was calculated as [IPA( 0 )xIW(mm)x100]/[IL(mm)xstone size(mm 2 )xPelvicaliceal volume(mm 3 )].The mean stone size was 72,4±49,4 mm 2 . Overall stone-free rate was %80.There were no statistically significant difference in IPA, IL and IW values between patients with residual stones and stone-free patients, respectively (p=0.06,p=0.81,p=0.21). Also no statistically significant difference were found in stone size (p=0.27),total pelvicaliceal volume(p=0.06) and SWL parameters. However IPI index was significantly different between two patient groups (p=0.04).Stone Free (mean±SD)Residual(mean±SD)P valueLower IPA( 0 )46,8±15,240±7,60,06Lower IL7,9±46,8±20,81Lower IW4,9±2,65,4±1,30,21Lower IP index0,14±0,180,028±0,0190,04Stone size66,2±44,196,2±67,10,27Mean number of session1,6±0,81,6±0,580,87Mean energy16,9±1,218,3±1,10,06Mean number of shockwave2457,5±551,62785±7860,33Total pelvic volume of stone bearing kidney(range)2621,2(582-7037)1850(1505-17138)0,07Results of this study let us think that although every single anatomic variation might have some effect on the SWL outcome of lower caliceal stones in paediatric patient basis, combination of all these anatomic parameters with the stone size in a single index could be a more accurate predictive tool because every single anatomic feature was a part of whole.