In the Whitehall study, 18,388 subjects aged 40-64 years completed a questionnaire on intermittent claudication. Of these subjects, 0.8% (147) and 1% (175) were deemed to have probable intermittent claudication and possible intermittent claudication, respectively. Within the 17-year follow-up period, 38% and 40% of the probable and possible cases, respectively, died. Compared with subjects without claudication, the probable cases suffered increased mortality rates due to coronary heart disease and cerebrovascular disease, but the mortality rate due to noncardiovascular causes was not increased. Possible cases demonstrated increased mortality rates due to cardiovascular and noncardiovascular causes. This difference in mortality pattern may be due to chance. Possible and probable cases still showed increased cardiovascular and all-cause mortality rates after adjusting for coronary risk factors (cardiac ischemia at baseline, systolic blood pressure, plasma cholesterol concentration, smoking behavior, employment grade, and degree of glucose intolerance). Intermittent claudication is independently related to increased mortality rates. It is not a rare condition, and simple questionnaires exist for its detection. The latter can be usefully incorporated in cardiovascular risk assessment and screening programs.