OBJECTIVE: To evaluate outcomes of same sitting Bilateral Retrograde IntraRenal Surgery (SSB-RISRS) for kidney stone in patients aged ≥70 years. METHODS: We retrospectively reviewed patients with bilateral kidney stones who underwent SSB-RISRS in 21 centers (January 2015-June 2022). INCLUSION CRITERIA: patients aged ≥70 years, bilateral kidney stones diagnosed due to either unilateral or bilateral symptomatic presentation. Patients were divided into 2 groups. Group 1: patients aged 70-74 years, Group 2: patients aged ≥75 years. RESULTS: There were 86 patients in Group 1 and 60 patients in Group 2. There was no difference between the groups for gender, ASA score, BMI, comorbidities, presenting symptoms, and positive preoperative urine culture. Group 2 had a significantly higher proportion of recurrent stone formers (54.7% vs 35.0%, p = 0.03). A higher proportion of bilaterally pre-stented patients were present in group 2 (37.9% vs 18.6%). There was no difference in total operation time and rate of post-operative uni- and bilateral stent positioning. Surgery was discontinued in 15.1% and 18.3% of cases in groups 1 and 2, respectively (p = 0.773). Median length of postoperative stay was 2 days in both groups. The most frequent complication was fever requiring antibiotics and prolonged admission (10.5% in group 1 and 11.7% in group 2, p >
0.99). Sepsis rate was 2.3% patients in group 1 and none in group 2. 1.2% in group 1 required a blood transfusion due to hematuria. Bilateral SFR was similar (60.0% vs 47.7%, p = 0.194). CONCLUSIONS: SSB-RISRS in elderly patients demonstrated an acceptable safety profile with good bilateral SFR.