While investigators have a duty to provide research participants with summary findings at the end of a study, providing general information during the course of research is rarely considered. However, this raises an important ethical issue in the context of long-term studies such as cohorts or biobanks. We investigated this issue in the context of two ANRS cohorts of HIV-infected patients, AQUITAINE and COPILOTE. Face-to-face interviews were conducted with HIV patient representatives and research professionals concerning the delivery of information in the course of the research. Respondents stated that participants wish to be informed of research results (both aggregate and individual) but also expect general information about the cohort itself, research progression, and what their participation may provide. It was concluded that information provided during the course of the research may help participants to distinguish between care and research. The essential role of clinicians-investigators in providing information was emphasized.