To determine the patterns of adjuvant chemoradiotherapy use in elderly patients treated with definitive surgical resection for squamous cell carcinoma of the head and neck with extracapsular extension (ECE) or positive margins and determine whether an association with overall survival (OS) exists with adjuvant concurrent chemoradiotherapy (CRT). The National Cancer Database was queried to identify patients with SCC of the oral cavity, oropharynx, larynx, and hypopharynx who were treated with primary definitive surgery and adjuvant radiation therapy between 2004 and 2012. For elderly patients (aged >70 years) with pathology revealing ECE or positive margin, the benefit of concurrent chemotherapy was explored using multivariable Cox proportional hazards modeling. A total of 7349 patients were identified meeting study criteria, of whom 1187 were elderly (aged >70 years) with a median follow-up of 30.6 months. Of these elderly patients, 445 had ECE or positive margin and represent the study population, of whom 187 (42%) received CRT. Delivery of CRT in this cohort increased over the study period, and intensity modulated radiation therapy was associated with increased use of CRT (odds ratio 2.07; P=.004). Increasing age was associated with reduced use of CRT (odds ratio 0.88; P<.001). Chemoradiotherapy was associated with a significant improvement in OS on multivariable analysis (hazard ratio 0.74; P=.04) and a trend toward significance on inverse propensity score analysis (hazard ratio 0.78; P=.051). Three-year OS was 53.8% in the CRT group, compared with 44.6% in the adjuvant radiation therapy-alone patients. The use of adjuvant CRT is increasing among elderly patients with resected squamous cell carcinoma of the head and neck exhibiting ECE or positive margins. Chemoradiotherapy was associated with an improvement in OS on multivariable analysis but not propensity-weighted analysis. Among fit elderly patients with ECE or positive margins after definitive surgical resection, concurrent chemotherapy can be carefully considered.