In order to obtain the maximum benefit from breast cancer screening it is essential for every programme to reach high levels of sensitivity and specificity. This can only be achieved if skill and a comprehensive quality assurance system is applied to the entire process, involving each individual part of the programme. Monitoring of outcomes and continuous evaluation of the entire screening process are key operational objectives for a successful population screening programme. The aim of this document, born in the framework of the Italian Group for Mammography Screening (GISMa), is to propose a unique methodology for collecting and reporting screening data using commonly agreed terminology, definitions and classifications. The indicators considered are those referred to the entire screening process and its sequelae, such as organizational, logistic and performance indicators. The indicators are provided under form of a synthetic and easy to use card. Every card is structured in short sections: definition, aim of the indicator, the data necessary to build it, the summarizing formula, possible problems of interpretation, the acceptable and desirable standards (derived both from the experience of national and European breast cancer screening programmes).