OBJECTIVE: To describe measures of quality of life of elderly patients with isolated systolic hypertension at entry to a placebo-controlled randomized trial of antihypertensive treatment and to investigate factors associated with these. DESIGN: Cross-sectional analyses at entry to a randomized controlled trial. SETTING: Patients attending hypertension clinics or general practitioners' surgeries at 30 centres in 10 European countries. PATIENTS: Six hundred and thirty-one patients aged 60 years or more, with a sitting systolic blood pressure during the run-in phase of 160-219 mmHg, a sitting diastolic blood pressure below 95 mmHg and a standing systolic blood pressure of 140 mmHg or more. MAIN OUTCOME MEASURES: Cognitive function tests (Reitan Trail Making A and B), Brief Assessment Index (a measure of depressed mood) and four subscales from the Sickness Impact Profile (Ambulation, Social Interaction, Sleep and Rest and Housework). RESULTS: Poor quality of life was generally associated with increasing age, previous treatment with antihypertensive drugs, presence of cardiovascular complications and, among women, high diastolic blood pressure, higher consumption of alcohol and high body mass index. CONCLUSIONS: At entry to the trial there was considerable heterogeneity of patients in terms of measures of quality of life and cognitive performance. It remains to be determined whether these influence subsequent quality of life during randomized treatment.