Little is known about HIV infection risks and risk behaviours of refugees living in resource-scarce post-emergency phase camps in Africa. Our study at Nyarugusu Camp in Tanzania, covering systematically selected refugees (n = 1140) and refugees living with HIV/AIDS (PLWHA) (n = 182), revealed that the level of HIV risk of systematically selected refugees increased after displacement, particularly regarding the number having transactional sex for money or gifts, while radio broadcast messages are perceived to promote a base of risk awareness within the refugee community. While condoms are yet to be widely used in the camp, some refugees having transactional sex tended to undertake their own health initiatives such as using a condom, under the influence of peer refugee health workers, particularly health information team (HIT) members. Nevertheless, PLWHA were less faithful to one partner and had more non-regular sexual partners than the HIV-negative group. Our study revealed that community-based outreach by refugee health workers is conducive to risk behaviour prevention in the post-emergency camp setting. It is recommended to increase the optimal use of "radio broadcast messages" and "HIT," which can act as agents to reach out to wider populations, and to strengthen the focus on safer sex education for PLWHA; the aim being to achieve dual risk reduction for both refugees living with and without HIV/AIDS.