Purpose: To report on a project involving European and Latin American universities, focusing on curriculum greening. Design/methodology/approach: This paper presents the experiences gained in connection with the "ACES Project" which is a model of the implementation of sustainability principles in higher education, with a special emphasis on curriculum greening. This paper presents the principles and main results of the project, which involved 11 European and Latin American universities, with financial support from the ALFA programme of the European Commission. Findings: The paper identifies ten characteristics of the initial model of curriculum greening which were validated in the process and were interpreted in the paper. Research limitations/implications: The type of action-oriented research carried out in the context of the ACES Project, by means of cooperative efforts and the accumulation of diverse fields of knowledge, presented working difficulties which are different from those experienced by more homogeneous groups. Nevertheless, the knowledge generated is very consistent in response to environmental issues and problems and reflects the need for collaboration between all areas of knowledge in order to preserve and improve environmental conditions. Practical implications: The paper introduces not only the results obtained with the ACES model, but also ten components which characterise curriculum greening and may be used elsewhere. Originality/value: The approach used and the emphasis on international cooperation illustrate ways in which a multi-stakeholders project may be successfully undertaken. (Contains 2 figures and 1 note.)