Four lifestyle dimensions were described based on 20 dietary behaviours as well as information about smoking behaviour, alcohol consumption and physical activity levels, in a sample of about 8000 survey participants from a population-representative sample in Wales in 1990. The first lifestyle dimension, mainly described by frequent intakes of chips, pies and processed meats, fried foods, alcohol drinking and cigarette smoking, was associated with male gender, younger age and lack of University education. The second, mainly described by frequent intakes of green vegetables, fruit, fish, poultry and non-smoking, was associated with older age, social group I and University education. The third, mainly described by frequent intake of pasta and rice and a high activity level, was associated with younger age, University education, and being born outside the UK. The final lifestyle dimension was mainly described by frequent intake of cakes, biscuits and sweets, non-smoking, and low alcohol intake, but was only weakly associated with socio-demographic factors. Local area differences in lifestyle patterns were also found. The benefits to health promotion of considering lifestyle as a pattern of inter-related health behaviours, and addressing the underlying determinants of these behaviours at the personal, social and community levels, were reinforced by the findings of this study.