Materials/Methods: We identified cases of treatment-naïve p16(-) LA-HNSCC (stage III-IVB) of the oropharynx (31%), larynx (55%), and hypopharynx (13%) who received definitive (70 Gy) CTX-bioRT (n Z 35), CB-CRT (n Z 43), or CP-CRT (n Z 67) at our institution from 2009 to 2015. Variables with P < .05 on log-rank/Kaplan-Meier analysis were included as covariates in Cox proportional hazards modeling to adjust for potential confounders; variables included: concurrent systemic agent, sex, age, smoking history, T stage, N stage, performance status, and primary tumor site. Results: We identified 145 cases: 107 men (73.7%), median age 60 years (range, 41-87), T3 (63.4%), and N2b (56.6%). There were no statistical differences in sex, age, smoking history, T stage, N stage, performance status, or frequency of primary site among the groups. The most common reasons for CP ineligibility were hearing loss (41.0%), medical comorbidities (35.9%), and renal disease (9%). Median follow up was 3 years. Locoregional control (LRC), distant metastasis-free survival (DMFS), recurrence-free survival (RFS), and overall survival (OS) at 3 years were not statistically different between those treated with CB or CP-CRT. When compared to CTX-bioRT, CB-CRT improved 3-year LRC (81.5 vs 40.0%; P Z .001), RFS (76.9 vs 38.3%; P Z .009), and OS (60.0 vs 55.2%; P Z .05), with a trend toward improved distant metastasis free survival (89.5% vs 65.8%; P Z .06). On MVA CB-CRT remained associated with improved LRC (HR 0.25, 95% CI 0.10-0.67; P Z .006), RFS (HR 0.30, 95% CI 0.12-0.76; P Z 0.01), and OS (HR 0.44, 95% CI 0.20-0.96; P Z .04) compared to CTX-bioRT. On subset analysis of non-oropharynx primary tumors, concurrent platinum agents (CP or CB) were associated with improved 3-year larynx preservation compared to CTX-bioRT (83.6 vs 47.1%; P Z .02). Conclusion: When patients cannot receive CP, CB-CRT is an effective alternative in p16(-) LA-HNSCC. Furthermore, CB-CRT markedly improved LRC, RFS, and OS compared to CTX-bioRT and should be a preferred substitute for CP in this population. Prospective validation of these results is needed.