Ethnography as a resource for design has been a topic of debate within Participatory Design since the late 1980s when a group of anthropologically trained social scientists began interacting with computer scientists who were developing new approaches to cooperative design of information technology systems. While ethnographers participated in Participatory Design projects as early as 1984 (cf. Florence project, Bjerknes and Bratteteig 1995), the question of the appropriate relation between studying the work practices of the workers for whom new technologies are being developed and directly engaging workers in design became a central concern within Participatory Design when US-trained anthropologists began interacting with Scandinavian Participatory Design researchers (Blomberg et al. 1993). What emerged from these interactions was a general consensus that it was useful to combine the study of work practice with the iterative design of workplace interventions and that both of these activities required the investment and direct participation of workers. More recently this view has been extended to include the design of interventions for domestic and community spaces. The challenge for those working within the cooperative design tradition has been to develop ways of integrating ethnography in Participatory Design (Bødker and Kensing 1994), while ethnographically trained researchers have looked for ways of incorporating iterative design into their field studies (Blomberg et al. 1997; Suchman et al. 1999). In the ensuing years the boundary between ethnographic research and design has continued to be explored and (re) defined, and throughout ethnography has remained an important component of Participatory Design. This chapter explores the history of ethnography in Participatory Design, the varied approaches that have been developed to connect ethnography and cooperative design, and the association this particular history has with the more general question of the relation between the sensibilities, commitments and requirements of design and of ethnography.