[Planning of a prospective study with a biological bank]

This present work aims to give a critical description of the organization and operative aspects of project ORDET (prospective study on diet and hormones in the aetiology of breast cancer). A number of problems which could arise when carrying-out a prospective study are described: they concern participant recruitment, laboratory organization, planning of a biological bank plus relative security checks in order to ensure full workability and personnel standardization in questionnaire administration and anthropometrical measurements. The methods adopted by ORDET, or at least some of them, could be useful for those engaged in the planning phase of a similarly designed project using a biological bank.