In recent years, there has been a marked increase in paediatric stone disease because of the changes in dietary habits and a more sedentary lifestyle. 1 Paediatric urolithiasis has a recurrent nature because it is frequently associated with metabolic or anatomical disorders or infectious conditions. 2 The rising incidence of the disease with its recurrent nature emphasises the need for minimally invasive therapeutic options. Among the options, there are extracorporeal shock wave lithotripsy (SWL), percutaneous nephrolithotomy (PCNL), semirigid ureterorenoscopy (URS) and flexible retrograde intrarenal surgery (RIRS). 3 With the availability of smaller size instruments, RIRS became an attractive option also for children. Within years, a significant experience has been accumulated. Several previous studies reported different factors affecting the stone-free rates (SFR). 4 Stone size,