Qualitative health researchers immerse themselves in the settings that they are studying. This immersion involves personal interaction with their participants, with the result that the boundaries between the researcher and the group of people under study can easily become blurred. Although health researchers have been undertaking qualitative research for many years, recognition of boundary issues inherent in this type of research have received little attention. To investigate such issues, the authors conducted interviews with 30 qualitative health researchers. A grounded theory analysis of the interview transcripts revealed that researchers can identify a number of boundaries in their research, including the boundaries between researcher and friend, researcher and counselor or therapist, and professional boundaries. The authors discuss the findings and offer recommendations for qualitative health researchers involved in researching sensitive topics, including the need for researchers to consider the impacts that undertaking research might have on them.