The objective of this study was to estimate the prevalence of undiagnosed impaired glucose homeostasis in hypertensive subjects in the general population. The most reasonable screening strategy for glucose disorders was also assessed. We carried out an oral glucose tolerance test for 1106 hypertensive subjects aged 45 to 70 years without previously diagnosed diabetes or cardiovascular disease. Blood pressure, waist circumference, body mass index, and plasma lipids were also measured. Type 2 diabetes was found in 66 (6%) of the subjects, impaired glucose tolerance in 220 (20%), and impaired fasting glucose in 167 (15%). If we had carried out an oral glucose tolerance test only for those hypertensive subjects with fasting plasma glucose >or=5.6 mmol/L, we would have missed approximately 40% of the patients with impaired glucose tolerance. The International Diabetes Federation criteria of metabolic syndrome identified 96% of all the cases of type 2 diabetes and 88% of all the cases of impaired glucose tolerance. The prevalence of central obesity was alarming: 90% of the women and 82% of the men had a waist circumference >or=80 cm or >or=94 cm, respectively. Impaired glucose homeostasis and central obesity are common in hypertensive subjects. An oral glucose tolerance test is reasonable to carry out at least for the hypertensive subjects with metabolic syndrome. Weight stabilization is an important goal to treat hypertensive patients.