The aim of the present study was to investigate the associations between number of missing teeth (expressing sustained oral infections) and diagnosed ischaemic heart disease using cross-sectional data from 1384 men aged 45-64 years. The study population was derived from a representative sample of adult Finns. Ischaemic heart disease was considered to be present in those with angina pectoris or previous myocardial infarction, whether definite or possible. A tooth was recorded as missing if none of it was visible or could be felt with an instrument. According to multiple linear analyses, the variation in ischaemic heart disease was independently explained by age, clinical diagnosis of arterial hypertension, geographical area, educational level and number of missing teeth. Smoking and cholesterol were not significant explanatory factors. The explanation for the observed association between missing teeth and ischaemic heart disease is that they may share a common behavioural background factor. There may also be a more direct causal relationship between the phenomena.