In order to explain the higher prevalence of fractures in urban compared with rural areas, 782 residents in the city of Malmö, Sweden and 486 inhabitants from the nearby rural municipality of Sjöbo were invited to participate in a sex- and age-matched cross-sectional study on life-style differences; 73 and 80% respectively responded. Responders answered a questionnaire on medical and social background and were interviewed on past and present physical activity. The men and women of the rural area were found to be significantly more active physically at work and during spare time. Housing was larger in the rural area. For women, these differences are decreasing in the younger age groups. Bone mass was found to be correlated to heavier work load for men. Other life-style variable such as dairy calcium intake, coffee drinking, estrogen medication, and morbidity, could not explain this difference. Higher prevalence of fractures in the city could therefore be explained by physically less active life-style.