There have been few prospective epidemiological studies of asymptomatic hyperglycaemia as a risk factor for cardiovascular disease and all causes mortality in women. Gender-specific all causes, cardiovascular disease (CVD), ischaemic heart disease (IHD) and stroke mortality rates and relative risks for asymptomatic hyperglycaemics (top 5%) have been compared to normoglycaemics (bottom 95%) during a mean follow-up of 11.6 years (range 10-14) among 4696 men and 5714 women aged 45-64 at entry in the west of Scotland. Univariate analysis showed that asymptomatic hyperglycaemia was associated with increased risk of all causes, CVD, IHD and stroke mortality in both genders. The degree of this association was greater in women than in men. Using multiple logistic regression (MLR) analysis to take into account differences in age, systolic (SBP) and diastolic blood pressure (DBP), serum cholesterol, body mass index (BMI), and cigarette smoking, high causal blood glucose level was still a significant risk factor for CVD mortality in both genders. It was also a significant risk factor for all causes, IHD and stroke mortality in women but not in men. This study shows that to a lesser degree asymptomatic hyperglycaemia shows the same gender differentials in risk of mortality as have been demonstrated amongst known diabetics.