•Selenium seems to be a crucial nutrient for HIV-infected individuals. It is a potent inhibitor of HIV replication in vitro. . . More than 20 papers report a progressive decline in plasma selenium in parallel with the on-going loss of CD4 T cells in HIV-1 infection. This decline in selenium occurs even in early stages of disease when malnutrition or mal-absorption cannot be a factor. In fact, plasma selenium is a strong predictor of the outcome in HIV infection.