<jats:p> 12041 </jats:p><jats:p> Background: To provide optimal treatment for older cancer patients, it is necessary to carry out a geriatric assessment (GA) to evaluate geriatric syndrome. However, GA is not widely performed because it requires expertise. In this ENSURE-GA study, we evaluated if providing a GA summary and recommendations for GA-guided interventions using a novel tablet-based questionnaire system improved satisfaction about communication with physicians for older patients with non-small-cell lung cancer (NSCLC). Methods: Patients with NSCLC who were incapable of radical treatment aged 75 or older were enrolled. All patients underwent a standardized GA using a tablet before starting treatment. Participating institutions were cluster-randomized into the intervention group and the control group. In the intervention group, GA summary and recommendations for GA-guided interventions were immediately returned to guide physicians in selecting treatments and interventions. The control group did not provide a GA summary. The primary outcomes were difference in patient satisfaction pre-treatment and percent change pre- and post-treatment according to the HCCQ questionnaire. Results: A total of 1,021 patients from 78 institutions in Japan were enrolled between 2019–2022. There were no differences in patient backgrounds between the intervention group and the control group: mean age 80.1 yrs. vs. 80.0 yrs.; male 64.1% vs. 66.8%; adenocarcinoma 70.4% vs. 64.8%; and performance status 0-1, 82.4% vs. 79.0%, respectively. All GA domain evaluation results, such as ADL and cognitive function, also did not differ between the two groups. Pre-treatment satisfaction scores were significantly higher in the intervention group than in the control group (29.9 vs. 29.1, p = 0.003). There was no significant difference in the mean percent change between the two groups (-0.13 vs. 2.38, p = 0.165). Conclusions: Providing the oncologist with a GA summary and recommendations for GA-guided interventions improved patient satisfaction from the start of treatment. A novel system using a tablet may be effective at promoting GA more widely. Clinical trial information: UMIN0000037590 . </jats:p>