Since the early 1990s, colposcopy of the vagina and cervix has been used in the development of vaginal products in order to detect epithelial changes that may increase the likelihood of HIV or acquisition of other sexually transmitted diseases. As part of a continued effort to examine and define the role of colposcopy in a research setting, the Contraceptive Research and Development Program (CONRAD) and the International Working Group on Microbicides (IWGM), in association with the United Nations Program for AIDS (UNAIDS) sponsored a conference entitled, 'The Use of Colposcopy in Assessing Vaginal Irritation in Research', held in Washington, DC in January 1999. This is a report of that conference. The World Health Organization's colposcopy procedure and nomenclature, published in 1995, were reviewed and changes were recommended. The revised procedure involves colposcopic examination of the external genitalia, naked eye examination of the cervix, fornices, and vaginal walls, followed by lavage and colposcopic examination of those areas, and sampling as appropriate for microscopic examination. Revised nomenclature replaces the terms used for findings with descriptions of what is actually seen. Digital video imaging and testing for inflammatory markers may be adjuncts to colposcopy and should be further studied. Other areas requiring additional research include the natural history of colposcopic changes, factors other than product use that may affect colposcopic findings, the clinical significance of findings, and the procedure which best assesses these findings.