Mild hypertension (grade 1 or stage 1 hypertension) is defined as a systolic blood pressure of 140-159 mm Hg or a diastolic pressure of 90-99 mm Hg. According to current guidelines, patients with mild hypertension can be at low, medium, high or very high risk depending on the presence of other risk factors, target organ damage and associated cardiovascular or renal conditions. Guidelines recommend prompt initiation of antihypertensive treatment in patients at very high risk because of associated clinical conditions and this recommendation is strongly supported by the literature. Also patients at high risk must be treated without much delay, but it should be mentioned that the evidence is stronger for patients who are at high risk because of diabetes mellitus, than for patients at high risk because of left ventricular hypertrophy or the accumulation of >or = 3 other risk factors. Patients at low and medium risk should be followed up and given advice on nonpharmacological measures and treatment should only be initiated in cases of persistently elevated blood pressure. However, this advice is based on indirect evidence and is currently not supported by randomised controlled trials. A survey on treatment of hypertension and implementation of World Health Organization/International Society of Hypertension (WHO/ISH) guidelines in primary care revealed that, respectively, only 20% and 33% of elderly men with mild hypertension at medium and high risk were treated with antihypertensive drugs and that this prevalence amounted to 67% in patients at very high risk; the prevalence was higher in patients with higher levels of blood pressure in each risk category.