Objective. To test the ability of the Theory of Planned Behaviour (TPB) to predict attendance for breast cancer screening and reattendance 3 years later, using data from a prospective longitudinal study. Method. A total of 1215 women who had never had breast screening completed a postal questionnaire sent to them shortly before they were to receive their first invitation for X‐ray mammography in the UK's National Health Service Breast Screening Programme. The questionnaire included items to tap attitude, subjective norm, perceived behavioural control and intention to attend. Attendance and then reattendance 3 years later were monitored from screening clinic records. Results. Two main results are reported. (1) Intention and first‐time attendance were predicted successfully from the TPB, and attendance was the single predictor of reattendance 3 years later. (2) The TPB was able to distinguish between intenders who attended and those who did not. Conclusion. The implications of the results are considered both for theory and for policy and practice. Particular attention is paid to the possibility of designing interventions to increase attendance and reattenda