In a study of lifestyles and health of the adult population of some Oxfordshire villages, data were collected upon the usual sleep duration and quality, smoking and drinking habits of 725 men and 759 women. A strong negative association has been found between cigarette smoking and sleep duration on both sexes, and between alcohol consumption and sleep duration in men. There is no equivalent association between drinking or smoking and reported poor quality sleep. While these findings do not prove a causal relationship, the absence of complaints of poor quality sleep among the smokers and drinkers suggests that these habits are not simply the correlates of underlying psychological problems leading to insomnia.