Following the publication of the Forrest Report in 1986. the Department of Health has established a national breast screening programme in the United Kingdom, to be fully implemented in 1990. Women aged between 50 and 64 years will be invited to undergo mammographic screening on a 3-year cycle. Funding has been allocated on the basis that a basic screening unit will serve a population of half a million and that specialist assessment centres will cover the work from up to three basic units. The organization of screening services requires careful planning and close cooperation between specialties; histopathologists and cytopathologists must ensure that they are fully consulted. There will be a considerable impact on laboratories and appropriate funding and manpower are required for the additional workload. Pathologists will be asked to provide a specialist service in the interpretation of diagnostic samples from such techniques as fine needle aspiration cytology and needle localization biopsies. Diagnostic difficulties will be encountered in the assessment of impalpable screendetected abnormalities and special training in breast screening is being provided. To ensure the success of the programme a national quality assurance scheme is being implemented. This will include validation of pathology data through regional coordinators.