A new article by Simon Collins and Nathan Geffen examines the evidence on when people with HIV should start treatment. The recent momentum to initiate treatment at a CD4 cell count above 350 cells/mm3 is driven by the potential population benefits of antiretroviral treatment reducing infectiousness together with operational concerns. These are important. However, the clinical benefits and risks for the person taking treatment should also be taken into account. These may vary depending on the background health setting. The authors conclude that the decision of when to start must be taken by the HIV-positive person in consultation with their health worker based on accurate information. That choice will vary depending on a person’s individual health, their reason to want to treat and the resources of the health-care facility. See under "Publications" for further information. Simon Collins works at HIV i-Base in London (UK). Nathan Geffen is in the AIDS and Society Research Unit within the CSSR, and manages GroundUp, our collaborative online media site.