Schulster M, et al. - A single-institution, prospectively kept database of endoscopic combined intrarenal surgery (ECIRS) was questioned for procedures performed 8/2017 to 1/2018 in order to ascertain stone clearance rates via ECIRS and evaluate the exactitude of intraoperative prediction of stone-free (SF) status in comparison with postoperative CT scan. A total of procedures were reviewed. Ninty-three individuals were endoscopically determined to be SF, of which 84 were validated SF through CT scan. Individuals with SF had markedly smaller stones in comparison with those with residual fragments. Preoperative stone burden and fluoroscopy time were the factors correlated with residual stones. In conclusion, ECIRS correctly prognosticates clinical SF status and may signify the necessity for supplementary CT scans. Furthermore, persistent with former studies, the initial stone size is the primary determinant of residual stone following percutaneous nephrolithotomy.