The year 2003 marks the 20th anniversary of the discovery of the human immunodeficiency virus type 1 (HIV-1). Among infectious disease-causing agents, HIV-1 is now the number one killer worldwide. Approximately 70% of the cases in the world are in sub-Saharan Africa, where in some regions, the seroprevalence of HIV-1 among adults exceeds 25%. Its high seroprevalence in some countries has raised concern that acquired immunodeficiency syndrome may create a threat to world peace. Despite developments in molecular biology, virology, immunology, and pharmacology, control of HIV-1 still awaits effective vaccines and microbicides. Because significant technologic advances still are needed to overcome the obstacles posed by HIV-1, we must find ways to expand and expedite proven prevention strategies and provide access to HIV-1 treatment for infected individuals throughout the world. Without doing so, the worst of this global pandemic will occur in the next decade before effective vaccines and microbicides are available.