Dental status and oral hygiene were investigated in a case-control study of 100 patients suffering from head and neck cancer and 214 age- and sex-matched controls. The dental status and paradontal status are poor in cancer patients. The number of decayed or missing teeth was significantly higher in our patients compared with controls. Furthermore, in the tumour group the rate of moderate or severe gingivitis and the presence of extensive tartar were significantly higher. These findings are mainly due to poor oral hygiene. Few of the cancer patients ever brushed their teeth, and the number of dental check-ups was significantly lower than in control subjects. Poor oral hygiene is predominantly an expression of self-neglect due to chronic alcohol consumption, which was present in nearly all of our patients. Furthermore, it seems to be related to an unsatisfactory health education in the lower social strata, to which most of cancer patients belong.