HIV testing and counseling services in Africa began in the early 1990s, with limited availability and coverage. Fears of stigma and discrimination, complex laboratory systems, and lack of available care and treatment services hampered expansion. Use of rapid point-of-care tests, introduction of services to prevent mother-to-child transmission, and increasing provision of antiretroviral drugs were key events in the late 1990s and early 2000s that facilitated the expansion of HIV testing and counseling services. Innovations in service delivery included providing HIV testing in both clinical and community sites, including mobile and home testing. Promotional campaigns were conducted in many countries, and evolutions in policies and guidance facilitated expansion and uptake. Support from President's Emergency Plan for AIDS Relief and national governments, other donors, and the Global Fund for AIDS, Tuberculosis, and Malaria contributed to significant increases in the numbers of persons tested in many countries. Quality of both testing and counseling, limited number of health care workers, uptake by couples, and effectiveness of linkages and referral systems remain challenges. Expansion of antiretroviral treatment, especially in light of the evidence that treatment contributes to prevention of transmission, will require greater yet strategic coverage of testing services, especially in clinical settings and in combination with other high-impact HIV prevention strategies. Continued support from President's Emergency Plan for AIDS Relief, governments, and other donors is required for the expansion of testing needed to achieve international targets for the scale-up of treatment and universal access to knowledge of HIV status.