Public policy debates, about HIV and prevention policy, have tended to occupy positions at the extremes of the two camps of rational choice, theorists and structuralists. This paper argues that the concept of hope may offer a way through this policy and paradigmatic log-jam. Hope is an individually measurable concept, which serves to link the ecological concept of risk environment with that of individual choice. It may be extended into broader understandings of the social epidemiology of infectious diseases. Use of an operationalised concept of hope also offers a possible way forward for rapid community diagnosis and participation in policy development, because it is immediately and intuitively accessible at three often separated levels: the individual actor, the researcher and those acting in the policy arena.