The global impact of human immunodeficiency virus and acquired immunodeficiency syndrome (HIV/AIDS) is increasing and traditional preventative 'safe sex' strategies do not seem to be slowing the spread of this virus. With an efficacious vaccine at least a decade away, the only strategy to avoid the ever-increasing cost of highly active antiretroviral therapy (HAART) is to develop new methods that prevent virus transmission. Microbicides are topically-applied molecules that disrupt the HIV cycle and block infection. This review discusses the current state of the art in microbicide development, looking at the most clinically advanced microbicides and those at earlier development stages based on their mechanisms of action. The socioeconomic impact of microbicide use is also considered, as this will determine whether microbicides are taken up and used consistently by the target population.