Life expectancy is increasing in most developed countries, in part due to improved socioeconomic conditions and in part to advances in healthcare. It is widely acknowledged that the promotion of healthy ageing by delaying, minimizing or preventing disabilities or diseases is one of the most important public health objectives in this century. In contrast to the menopausal transition in females, we know relatively little about the contribution of androgens and anabolic hormones to the quality of ageing in men. The European Male Ageing Study (EMAS) is a multicentre prospective cohort designed to examine the prevalence, incidence and geographical distribution of gender-specific and general symptoms of ageing in men, including their endocrine, genetic and psychosocial predictors. Men aged 40-79 years were recruited from eight European centres: Florence (Italy), Leuven (Belgium), Lodz (Poland), Malmö (Sweden), Manchester (UK), Santiago de Compostela (Spain), Szeged (Hungary) and Tartu (Estonia). Subjects were recruited from population registers and those who agreed to take part completed a detailed questionnaire including aspects of personal and medical history, lifestyle factors and sexual function. Objective measures of body size, cognition, vision, skeletal health and neuromuscular function were obtained. Blood and DNA specimens were collected for a range of biochemical and genetic analyses. After an average of 4 years, it is planned to resurvey the participants with similar assessments. A total of 3369 men with a mean age of 60 +/- 11 years were recruited. The mean centre response rate was 43%, and highest in those aged 50-59 years. Those who participated were marginally younger than those who were invited but declined to participate (60.0 vs. 61.1 years). Participants left education slightly later than a sample of non-participants, though there were no consistent differences in levels of general health, physical activity, or smoking. EMAS will provide new population-based data concerning the main features that characterize ageing in men and its critical determinants, particularly with reference to age-related changes in hormone levels. Such information is an important prerequisite to develop effective strategies to reduce age-related disabilities and optimise health and well-being into old-age.