To determine the primary radiation treatment and salvage outcomes for patients who were treated definitively for oral cavity squamous cell carcinoma (OSCC) without primary surgery. All OSCC patients treated with curative intent involving radiation therapy in our institution between Jan 2005 and Dec 2014 were reviewed. Data elements were extracted from the prospectively collected H&N Anthology of Outcomes database, including TNM, 7thedition UICC/AJCC staging, radiotherapy dose fractionation, dates of recurrence and death. Local control (LC), regional control (RC), distant control (DC) and overall survival (OS) were compared between clinical node positive (cN+) and negative (cN–) patients. Of 557 consecutive OSCC patients treated with curative intent involving radiotherapy, 108 patients (19%) received radical definitive radiation therapy instead of primary surgery. Of 86 patients who were operable, 71 (66%) patients underwent primary radiation as a joint decision from the surgical and radiation oncologists to avoid initial extensive surgery, due to oropharyngeal involvement or to preserve oral functions; 15 (14%) patients declined upfront surgery and six of these would consider salvage if necessary. The remaining 22 inoperable patients (20%) either had significant medical comorbidities (n=14, 13%) or technically inoperable disease (n=8, 7%). A total of 76 patients were treated with definitive intensity modulated radiotherapy (IMRT) alone and 32 with concurrent chemo-radiotherapy. The radical radiation dose fractionations used were 70Gy/35# (n=64, 59%), 60Gy/25# (n=37, 34%), 64Gy/40# BID over 4 weeks (n=5, 5%) and 66Gy/33# (n=2, 2%). 7 patients were clinically Stage I (6%), 22 Stage II (20%), 21 Stage III (20%), 51 Stage IVA (47%) and 7 Stage IVB (6%). The number of T1, T2, T3, T4a, and T4b patients was 10, 30, 24, 37, and 7, respectively. The number of N0, N1, N2a, N2b, N2c, and N3 patients was 56, 14, 3, 18, 16, and 1 respectively. Median follow up was 52 months (4.3years). Outcomes at 3 years were as follows: LC of cN– (n=56) and cN+ (n=52) cohorts were 76% and 71% (p=0.69) respectively, RC of 96% and 90% respectively (p=0.446), DC of 98% and 81% respectively (p=0.004), and OS of 65% and 44% (p=0.005) respectively. Seventeen (15%) patients received subsequent surgery and 11 (64%) were successfully salvaged to achieve LRC. Of the 11 patients who were salvaged, only one patient went on to fail distantly after salvage surgery. Almost 1 in 5 OSCC patients treated with curative intent at our institution received radical definitive radiotherapy without upfront surgery, most commonly for the purpose of organ preservation. OSCC patients treated with definitive radiation had reasonable rates of disease control, but poor 3-year overall survival rates were observed. Local relapse was the most common pattern of failure in cN– patients, and both local and distant relapse were common patterns of failure in cN+ patients.