Purpose: The purpose of this paper is to examine the issues involved in designing appropriate problems or scenarios suitable for sustainable development (SD) education, in the context of problem-based learning (PBL) and experiential learning. Manchester's PBL approach to interdisciplinary Education for Sustainable Development (ESD) has been well reported, for example, in papers at the Educating Engineers in Sustainable Development conference in 2008. This paper poses the question: to achieve transformational education, is design of student problems for ESD itself a wicked problem? The design process that has been used to generate ESD projects for one PBL unit is reflected upon, to share good practices and highlight points of ongoing contention. Design/methodology/approach: Working from the background to the original pilot project to develop an inter-disciplinary course to heighten student skills in sustainability and change management, the paper looks at some of the theoretical approaches taken to the design of PBL scenarios and tries to place these in the context of education for SD. Findings: The initial project found that using inter-disciplinary, problem-based approaches to embedding SD in the curriculum is not only practicable but also desirable. However, the approach to design of problem scenarios has to be adjusted to the nature of the "wickedness" of sustainability issues and be appropriate to the student cohort and institution. Research limitations/implications: The approaches are felt to be applicable to a much wider range of situations than is demonstrated in the paper but, clearly, the findings can only be grounded on the particular situation of the project. Originality/value: The 2006 curriculum development action research project was intended to help other institutions to replicate the process but, much of the external attention since that time has focussed, inappropriately, on simply re-using the scenarios that were described in the initial project rather than applying the design process that has been developed in order to devise new scenarios more appropriate to another course or institution. (Contains 2 tables and 1 figure.)