It was the four training activity addressed to the teachers of eight centres of “The Barcelona School Agenda 21 Programme”, which are participating in a project for developing Waste Prevention Plans in schools. The objective of this waste project is to give support at teachers by 4 training group activities and 16 individual implementation visits at schools (2 visits at each school, 2 x 8 = 16 visits). At the end of the project, in addition to an individual Waste Prevention Plan of each school, a guide on “How to develop a Waste Prevention Plan in schools”, will be written with the experiences and inputs of these eight centres. The aims of this 4rd session were firstly, explain the actions done in the each Waste Prevention Plan of each school and also the actions planned in their future and, secondly, evaluate the process in order to have clues to choose the important content for the final guide. Finally, the teachers answered the evaluation form for general events (table 6 of the D5.2. Evaluation Instruments) and the main answers related to organization, content and results were very positive. Some of the good comments were: the main value of the project have been the lot of examples of prevention actions in schools and the importance to quantify them, and another comment not so good was the adjusted calendar.