Background: Radical intent treatment in older patients with head and neck squamous cell carcinomas (HNSCC) is complicated by several factors such as comorbidities and multiple concomitant medications. Assessing vulnerabilities in various domains may enable decision-making. Methods: Patients aged over 60 years with locally advanced HNSCC planned for chemoradiation seen at the geriatric clinic in Tata Memorial Hospital, Mumbai, from June 2018 to December 2022 were identified from the clinic database. Demographic characteristics, treatment details, toxicity and outcome data were retrieved from our hospital electronic medical records. Results: Between June 2018 and December 2022, 87 patients with HNSCC planned for chemoradiation after multimodality joint clinic discussion underwent geriatric assessment (GA) at our clinic. 18 patients (20.6%) underwent radiotherapy alone after being deemed unfit for concurrent chemotherapy, and 50 patients (57.4%) ultimately received concurrent chemoradiation. 15 patients (30%) were vulnerable in the domain of function and falls, 21 (42%) in comorbidities, 3 (6%) in psychological, 1 (2%) in cognition, 6 (12%) each in polypharmacy, nutrition, and social domains, and 8 (16%) in the domain of fatigue. 41 patients (82%) were fit, with 2 or fewer vulnerabilities on GA, and 9 patients (18%) were frail, with 3 or more vulnerabilities. Decision on chemotherapy regimen was made after GA results in 36 patients (72%). In 8 patients (16%), the tentative chemotherapy regimen was changed as per the GA results. Common regimens used were cisplatin 40mg/m² weekly (28%), nimotuzumab (22%), cisplatin 100mg/m² 3 weekly (10%), docetaxel (8%), and carboplatin alone (6%). The median Cancer Aging and Research Group (CARG) risk score was 6, corresponding to a 44% predicted risk of grade 3 or higher toxicities from a combination chemotherapy regimen. 34% (n = 17) patients developed grade 3 or 4 toxicities, most commonly mucositis (14%) and neutropenia (12%). Toxicity led to dose delay in 9 patients (18%), and discontinuation in 10 patients (20%). Median progression-free survival (PFS) was 18.0 months, (95% CI: 0.9-19.0 months) and median overall survival (OS) was 31 months (95% CI: 4.0-57.9 months). On Cox regression analysis, factors significantly associated with poorer PFS were vulnerabilities in the domain of nutrition (p = 0.04) and comorbidities (p = 0.03), lower G8 score (p = 0.021), and higher CARG score (p = 0.006), and for poorer OS were comorbidities (p = 0.04) and higher CARG score (p = 0.01). Conclusions: Geriatric assessment aids decision-making in older patients with locally advanced head and neck cancers warranting chemoradiation. Vulnerabilities in geriatric domains have survival implications, and identification may help improve outcomes. Clinical trial information: CTRI/2020/04/024675.