We read with great interest the recent article by Kruck et al. [1] on the comparative study of minimally invasive percutaneous nephrolithotomy (MIP), retrograde intrarenal surgery (RIRS) and shock wave lithotripsy (SWL) in renal stone treatment. In this article, authors compared clinical outcome, complications, stone-free rate (SFR) and stonefree survival with regard to stone size and localization. They concluded the significant advantages of the MIP and RIRS procedures for increased SFRs, lower risk of stone persistence and prolonged stone-free survival compared with SWL. We congratulate the authors for their work and thank them for bringing this debatable topic to our attention; however, we feel that some issues described in their paper need further discussion. Over the last decade, with the miniaturization of instruments in percutaneous nephrolithotomy and technological improvements in flexible ureteroscopes, working instruments and laser technology, RIRS, MIP and microperc techniques have become more attractive procedures for the treatment of nonbulky renal urolithiasis [2, 3]. Furthermore, in the recent years, there has been an increasing realization that the SWL has unpredictable and unfavorable results when comparing with other minimally invasive methods [4–6]. On a comparative study of RIRS and SWL, El-Nahas et al. [4] concluded the significant advantages of the RIRS procedure for higher stone-free rate and lower retreatment rate for the management of medium sized lower pole renal stones. Another three comparative studies, evaluating the outcomes of PNL and SWL, showed that the success rate was statistically higher, and retreatment or auxiliary procedures were less for PNL compared with SWL [5–7]. But in all these studies, PNL or RIRS was associated with an increased risk of complications compared with SWL. Similar results were reported in the present study by Kruck et al. [1]. Despite publishing these studies and clinical treatment guidelines, there are no universally accepted paradigms to treat renal stones, due to absence of robustly designed randomized controlled trials [8, 9]. Until the publishing of welldesigned randomized prospective large series examining the efficacy and safety of minimally invasive treatments, SWL will be the most valuable treatment option because of its noninvasive nature, low morbidity rate and high patient acceptance [3]. Therefore, current EAU guidelines recommend SWL remains the method of first choice for stones \2 cm within the renal pelvis, upper or middle calices and for stones\1.5 cm within lower pole calices [9].