This paper provides an overview of HIV viral loads in blood and genital fluids and how these relate to HIV transmission during sexual activity. Current knowledge around HIV viral loads and transmission are then discussed in relation to HIV disclosure laws in Canada. HIV counsellors and health care workers should ensure that their clients/patients are aware that blood viral load is not necessarily equivalent to genital tract viral load and that the development of drug resistance within the two compartments may be unrelated. This is an important factor in preventing the spread of HIV as well as for HIV-positive individuals in not unintentionally exposing themselves to potential legal repercussions.