The greatest potential for the chemoprevention of cervical cancer is in women with human papillomavirus (HPV) infection, an abnormal screening test or a non-invasive neoplastic lesion. Potential chemopreventive agents include micronutrients, antiviral agents and immune modifiers. Randomised controlled clinical trials have generally been small and the results have not been encouraging. Beneficial effects on neoplasia have been shown for a couple of agents that have since been abandoned due to adverse side-effects. Indoles were used successfully in a very small clinical trial of women with high-grade cervical intraepithelial neoplasia and a larger trial using diindolylmethane in women with mildly abnormal cervical smears is underway. Although definitive trials need to use a robust clinical endpoint (such as histology), all future trials should include biomarkers to study the subclinical effect of the study agent.