Trachoma causes one-quarter of the world's blindness and, although it has disappeared from many developed areas, it remains a major problem, especially in underprivileged rural areas in developing countries. Recent advances in the understanding of the molecular biology of chlamydia offer encouragement for the eventual development for an effective trachoma vaccine. Advances in the understanding of the epidemiology of trachoma, particularly of the importance of reinfection and the intrafamily transmission of infection, have led to the identification of the key importance of simple hygiene measures such as facial cleanliness in preventing the transmission of trachoma. Community-based health education intervention programs are being developed to assess the efficacy of a public health approach to the control of trachomatous blindness.