OBJECTIVE To evaluate if characteristics and abnormalities found at the electrocardiogram (ECG) are related to common cardiovascular risk factors included in the insulin-resistance metabolic syndrome. METHODS Cross-sectional. METHODS Tertiary university hospital. METHODS Over 2000 middle-aged males in whom ECG abnormalities were recorded, together with ECG characteristics measured in a random sample of men with no ECG abnormalities (n = 113). METHODS None. RESULTS All three components of the metabolic syndrome; elevated blood pressure, dyslipidaemia and hyperinsulinaemia were found to be related to the heart rate (P < 0.002) and the QRS-duration (P < 0.01) and inversely to the QoT-interval (P < 0.05), the early diastolic phase (P < 0.05) and the T-wave amplitude (P < 0.02). The components of the metabolic syndrome was furthermore found to be associated with the occurrence of T-wave abnormalities (n = 64, P < 0.01) and to a lesser degree also to the occurrence of Q-waves (n = 21). CONCLUSIONS The components of the insulin-resistance metabolic syndrome were related both to certain ECG characteristics in subjects with a normal ECG and to some ECG abnormalities. A raised sympathetic activity is likely to be the link between some of the described associations, whilst coronary heart diseases may explain others.