Characteristics of first-round attendees and determinants of reattendance in the Swiss mammography screening pilot programme (1993-1998) were investigated. Data on socio-demographic features, health preventive behaviour and history, prior screening round and referring physicians' attributes were collected at initial attendance among women enrolled in 1993-1995. First-round participants (n = 4,162) were prospectively followed through next screening round. Determinants of reattendance (second-round attendance among first-round participants) were identified by multivariate logistic regression models. The reattendance rate was high (80%). Women most likely to reattend were urban, Swiss residents with a true-negative first-round screening result. The more intensive the initial recruitment efforts, the lesser were the odds of reattendance. Mammography screening prior to screening enrolment increased reattendance. Having a gynaecologist, a female and a younger doctor as a referring physician was positively associated with reattendance. Mammography screening attendance is not only influenced by women-related factors but also by structural factors, and thus requires a global approach. For strategies aimed at improving the impact of organised cancer screening programmes, understanding and quantification of determinants of (re)attendance are key elements to consider.