This study aimed to evaluate sociodemographic and clinical factors influencing overall survival (OS) in patients with oral squamous cell carcinoma (OSCC). Medical charts of 547 patients with OSCC from a public hospital in northeastern Brazil seen between 1999 and 2013 were evaluated. Survival analysis was performed using the Kaplan-Meier method. The influence of age, sex, ethnicity, clinical stage, anatomical location, type of treatment, and comorbidities on the patients? prognosis was evaluated. Cox proportional hazards regression model was used to identify independent prognostic factors. The 5-year OS was 39%. Multivariate analysis showed that age < 40 years (HR = 2.20; 95%CI: 1.02-4.72) and a single treatment modality (HR = 1.91; 95%CI: 1.37-2.67) were associated with a poor prognosis, while early clinical stage resulted in better outcomes (HR = 0.38; 95%CI: 0.25-0.58). OSCC patients in advanced clinical stages, diagnosed at a younger age, and submitted to a single therapeutic modality have a poorer prognosis.