The development of HIV vaccines has been hampered by the lack of an animal model that can accurately predict vaccine efficacy. Chimpanzees can be infected with HIV-1 but are not practical for research. However, several species of macaques are susceptible to the Simian Immunodeficiency Viruses (SIV) that causes a disease in macaques that closely mimics HIV in humans. Thus, macaque-SIV models of HIV infection have become a critical foundation for AIDS vaccine development. Here, we examine the multiple variables and considerations that must be taken into account to use this NHP model effectively. These include the species and subspecies of macaques, virus strain, dose and route of administration and macaque genetics including Major Histocompatibility Complex molecules that affect immune responses and other virus restriction factors. We illustrate how these NHP models can be used to carry out studies of immune responses in mucosal and other tissues than could not easily be performed on human volunteers. Futhermore macaques are an ideal model system to optimize adjuvants, test vaccine platforms, and identify correlates of protection that can advance the HIV vaccine field. We also illustrate techniques used to identify different macaque lymphocyte populations and review some poxvirus vaccine candidates that are in various stages of clinical trials. Understanding how to effectively use this valuable model will greatly increase the likelihood of finding a successful vaccine for HIV.