After 25 years of evaluative activity, the Federal Office of Public Health used the occasion to obtain an overall picture of what has been achieved so far. A review of the lessons highlighted in the evaluation reports was therefore commissioned. An interpretive approach was applied to study the reports and draw out the key lessons in relation to a diversity of health policy areas. A desk-based analysis was used meaning that the findings could not be validated with the evaluators themselves, nor could the study attempt to understand how these lessons were ultimately received or acted upon by the various stakeholders. The approach focused on implementation processes. Through classifying the different types of lessons, we identified five dimensions. Together they cover the technical, theoretical and contextual expertise that the various stakeholders use to determine priorities and adjust actions. This provides a substantial knowledge base on “good and less good” practices. But successive evaluations also show that some lessons appear time and time again, which suggests that some knowledge is not adequately shared between the different policy areas or activity sectors. There is a clear need for devising a better knowledge management system, capable of assembling and classifying the lessons highlighted by evaluators in their reports. Such a system should then be accessible to the various public health actors; the staff of the Federal Office of Public Health as well as the relevant stakeholders, politicians, interested groups, and the public at large.