The aim of this study was to identify predictors of non-attendance in a population-based mammography-screening programme in central Sweden, on the basis of telephone interviews with 434 non-attendees and 515 attendees identified in a mammography register. Non-attendance was studied in relation to socio-demographic factors, indicators of general health behaviour, self-rated health and experience of cancer in others and own cancer or breast problems. Being single or being non-employed were the only important socio-demographic predictors of non-attendance. Non-attendance was more likely among women who never visited a dentist, had not visited a doctor in 5 years, had never used oral contraceptives or hormone replacement therapy, had never had cervical smear tests, never drank alcohol, smoked regularly, reported no breast cancer in family or friends or own breast problems. We conclude that socio-demographic factors alone do not appear to constitute strong predictors of non-attendance. General health behaviour and previous experience of cancer and breast disease seem to be more important factors. Our results suggest that in the setting of population-based outreach mammography programmes, previous contacts with the health care system and encouragement from health professionals represent determinants of attendance.