This paper explores qualitative research that aimed to understand how scientists encounter the science-policy boundary in the ordinary course of doing their research. In interviews, scientists sometimes referred to institutions whose role it is to stabilize the relationship between science and policy — boundary organizations as Guston (1999) has called them. Individual scientists, however, often engage in their own versions of `boundary work' between science and policy. The paper suggests that it may be useful to explore the implications of this more individualized, less institutionalized boundary work to understand better the shifting identity of contemporary science.