The incidence of oral cancer amongst young adults is increasing in many European and high incidence countries. The aim of this study was to evaluate the major risk factors for oral cancer in young adults using a case-control design. A sample of 116 patients aged 45 years and younger, diagnosed with squamous cell carcinoma of the oral cavity between 1990 and 1997 from the south east of England were included. Two-hundred and seven controls who had never had cancer, matched for age, sex and area of residence, were recruited. The self-completed questionnaire contained items about exposure to the following risk factors: tobacco products, cannabis, alcohol and diet. Conditional logistic analyses were conducted adjusting for social class, ethnicity, tobacco and alcohol habits. All tests for statistical significance were two-sided. The majority of oral cancer patients reported exposure to the major risk factors of tobacco and alcohol even at this younger age. The estimated risks associated with tobacco or alcohol were low (OR range: 0.6-2.5) among both males and females. Only smoking for 21 years or more produced significantly elevated odds ratios (OR=2.1; 95% CI: 1.1-4.0). Exposure associated with other major risk factors did not produce significant risks in this sample. Long term consumption of fresh fruits and vegetables in the diet appeared to be protective for both males and females. The results suggest that although this younger sample exhibit similar behavioural risk factors to older oral cancer patients, the low odds produced in addition to the relatively short duration of exposure, suggest that factors other than tobacco and alcohol may be implicated in the development of oral cancer in these younger patients.