The Hypertension in the Very Elderly Trial (HYVET) is a randomized double-blind trial of active antihypertensive treatment (indapamide 1.5 mg sustained release +/-2-4 mg perindopril) vs placebo in participants over the age of 80 years with a systolic blood pressure (SBP) of 160-199 mmHg during a placebo run-in period plus a diastolic blood pressure (DBP) of<110 mmHg. The trial has completed with 3845 subjects randomized and we report the baseline characteristics. The participants were a healthy group. The numbers smoking, drinking alcohol and having previous cardiovascular events were low, and their hypertensive status was not usually associated with the metabolic syndrome; 1.0% of the whole group had a total cholesterol over 8.0 mmol/l, 1.1% a blood sugar over 11.1 mmol/l (irrespective of anti-diabetic treatment) and 1.7% a serum urate over 460 micromol/l (women) and 0.6% over 520 micromol/l (men). A serum creatinine over 150 micromol/l excluded participants from the trial. The gender differences and age comparisons were as expected but the women had higher average total and high-density-lipoprotein-cholesterol blood concentrations. Those with prior cardiovascular disease had an excess of the known cardiovascular risk factors. The baseline characteristics provide a basis for further understanding of the HYVET results, which have been published recently.