Anecdotes have long suggested that caffeine-containing beverages and other personal habits and excesses trigger palpitations and cardiac extrasystoles. We took the opportunity of a systematic population survey of 7311 men, aged 37-57 yr and free of any history of heart disease or diabetes, to examine the association of ventricular premature beats (VPB) with food and drink, cigarette smoking and sleep habits. Blood pressure and serum cholesterol were also measured and a 2-min rest electrocardiogram recorded at a screening station. In multiple regression analysis a significant relationship with prevalence of VPB was found for age and for the average daily number of cups of tea or coffee consumed, adjusting simultaneously for the influence of other factors. Heavy coffee consumption (≥9 cups/day) was associated with more than twice the likelihood of VPB being present at any age, compared to light consumption (≤2 cups/day) or abstinence.