This exploratory paper examines the relationship between Participatory Design (PD) and Sustainability as it emerges from the Participatory Design Conference (PDC). The reinvigorated political agenda of PD, together with the enlargements of its application domains and scopes of interest, calls for reinvigorating the early concerns of the field for long-term, durable, and positive change. The objective of this paper is to explore what "sustainability" means in and for the field. The study is based on a literature review of the PDC Proceedings and it provides both an outline of the structural aspects of the literature and a mapping of three use patterns of the concept: PD for Sustainability; Sustainability of PD Practice; and Sustainability of PD Results. Based on our interpretation of these patterns we also provide a general definition of sustainability. We believe the findings of this paper can support PD scholars in conceptualizing sustainability and to position their works in relation to it.