Most squamous cell carcinomas of the oral cavity and oropharynx are not diagnosed until they have attained at least the T2 stage (greater than 2.0 cm). This study identifies factors which may contribute to the delayed diagnosis of these tumors, despite the fact that they frequently arise at sites readily accessible to examination. Personal interviews of 149 patients with oral and oropharyngeal squamous cell carcinoma revealed delays by patients of one day to more than one year (mean, 17 weeks) before seeking care. Furthermore, delay by doctors occurred in 45 instances (30%). Neither short nor long delays had a statistically significant relationship to tumor T stage at the time of diagnosis. The length of patient delay was also not related to age, gender, amount of education, or history of alcohol consumption. The authors concluded that the early carcinomas were probably asymptomatic and subsequent manifestations were commonly misinterpreted as benign or innocuous oral/dental problems. These inconspicuous or misleading perceptions may be primarily responsible for the advanced stages of these tumors at the time of discovery. Emphasis must, therefore, be placed upon gaining access to high-risk individuals for periodic oral and oropharyngeal examinations and upon educational efforts to increase the skill of primary health care providers in recognizing this problem.