A study in Babol, Islamic Republic of Iran, used a questionnaire to gather information on knowledge about oral cancer and its risk factors and to evaluate the efficacy of an educational brochure. From a community sample of 400 people, 76.0% had no knowledge of oral cancer. Mean knowledge score before the education intervention was 1.47 (standard deviation 3.40) out of 10. Knowledge about oral cancer was not associated with age, sex or education level but urban residents had better knowledge than rural residents. Mean knowledge score improved significantly by 5.92 (SD 3.30) at 1 month after the intervention among the 226 respondents who had read the brochure.