Vaginal spermicides have microbicidal properties that suggest their usefulness in helping to protect against human immunodeficiency virus (HIV) and other sexually transmitted infections. Laboratory, animal, and clinical investigations also support this notion. Because of the importance of identifying additional methods to protect against these infections, however, better information is needed on these female-controlled methods. A consistent set of laboratory standards is needed to evaluate the in vitro activity of existing and future virucides. Further evaluation of such areas as the actions of virucides and vehicles on different anatomical sites and safety studies to better judge determinants of toxicity are needed. Clinical studies might compare efficacy of spermicides and condoms in prevention of HIV and other sexually transmitted diseases as well as investigate psychosocial considerations that determine suitable candidates for vaginal virucides, how they are used, and how their use might be improved.