Objective: In this study, we aimed to evaluate and compare the effects of retrograde intrarenal surgery (RIRS) and schok wave lithoripsy (SWL)interventions on renal functions by analyzing glomerular filtration rate (GFR) values.Materials and Methods: A total of 95 patients, who underwent RIRS or SWL in 2017 at Gülhane Training and Research Hospital, were included inthis retrospective study. Forty-six of these patients (48.4%) were in RIRS group and 49 (51.6%) were in SWL group. Preoperative, early-postoperative(on the first postoperative day) and late-postoperative (on the first postoperative month) GFR values were calculated using the “abbreviatedModification of Diet in Renal Disease” Method. Changes in GFR values after RIRS and SWL treatments were compared statistically.Results: When the early postoperative and late postoperative GFR levels were compared, a statistically significant difference was observed betweenthe groups (p=0.04 and p<0.001, respectively). For RIRS group, there was a 0.37±13.5 mL/min/1.73 m² increase and for SWL group, there was5.65±12.5 mL/min/1.73 m² increase in GFR values in the early postoperative period. There was a 2.40±14.1 mL/min/1.73 m² decrease in RIRS groupand 7.75±11.8 mL/min/1.73 m² increase in SWL group in GFR values in the late postoperative period. In general linear model, there was a statisticallysignificant difference in changes in GFR over time between RIRS and SWL groups (p=0.002). There was also a statistically significant difference whenthe changes in GFR over time were compared according to stone locations (p=0.02).Conclusion: RIRS is associated with less improved GFR in comparison with SWL. SWL should be considered as first line treatment for kidney andureteral stones when considering the changes in GFR values comparing to RIRS especially for stones smaller than 20 mm.