Background: Up to 24% of patients (pts) newly-diagnosed with LA-HNSCC are 70 years old (yo). NCCN guidelines recommend a geriatric assessment to guide treatment decisions in this pts population. Comprehensive geriatric assessment (CGA) of older HNSCC pts was implemented at our institution in 2018. We evaluated the impact of CGA in treatment decision and outcome and compare it to a control cohort with no CGA treated within the same institution. Methods: Retrospective single-institution analysis of two consecutively-treated cohorts of newly-diagnosed elderly LA-HNSCC pts treated at the Catalan Institute of Oncology: a cohort treated based on CGA between 2018-2020; and a control cohort with no CGA treated based on physician criteria following tumor board decision between 2016-2018. Pts demographics and disease characteristics were obtained from our in-site prospective database. Treatment received (standard, adjusted, palliative-intent, best supportive care [BSC]), treatment completion rate (TCR) an overall response rate (ORR) after conservative treatment were collected and compared for both cohorts using chi-square. Results: A total of 197 pts were included: CGA cohort =81; Control cohort=96. Baseline characteristics were similar between cohorts (Table). Pts in CGA cohort were classified as fit (F) 35 (34.7%), medium-fit (MF) 51 (50.5%) and unfit (UF) 15 (14.9%) according to CGA results. CGA changed final treatment decision following tumor board in 31 % of the cases. Pts were more likely to receive standard treatment in the CGA cohort when compared control (36 vs 21%; p = 0.048), with no differences observed in TCR (84% vs 86%; p = 0.805). In pts who underwent conservative treatment, ORR was similar between CGA and control cohort (73.9% vs 66.7 %; p = 0.082), respectively. Tumor progression was the major cause of death in both groups. Conclusions: Older pts with LA-HNSCC who underwent CGA were more likely to receive standard treatment than those who did not, supporting the relevance of CGA for clinical decision-making in this pt population. No differences were observed in CRR, TCR or death cause. In-deep survival analysis are on-going.