Trachoma is an ancient scourge, described in the Egyptian Ebers papyrus in 1900 BC and well known to Hippocrates. The disease was endemic in Europe until well into this century, and would-be immigrants to the USA were screened for trachoma by examination of the everted upper eyelid on arrival at Ellis Island, New York. Those in whom the characteristic follicles were seen were put on the next boat back to Europe so great was the fear of what was clearly recognised to be a contagious condition. 1 2 Many of the eye hospitals in Europe, including Moorfields, were founded specifically to treat trachoma, and in 1937 Duke-Elder stated that “its importance as a source of human suffering, as a cause of blindness, and as a national economic loss over large tracts of the world’s surface, is second to none among diseases of the eye”. 2 Trachoma has now disappeared from Western Europe and North America as a result of improved living standards, but unfortunately there are many parts of the world where living standards have not improved, and do not seem likely to in the near future. Trachoma remains the third commonest cause of blindness worldwide after cataract and glaucoma; 150 million people are aVected, in 48 countries, and 6 million of these are blind. 3 The treatment for trachoma recommended by Duke-Elder, copper sulphate, was also used by the ancient Egyptians. But there have been several major advances in our understanding of the disease this century, and in 1997 the World Health Organisation announced a new initiative to eliminate trachoma as a cause of blindness by the year 2020. In this paper we review recent advances and the current state of knowledge about trachoma, and critically discuss the prospects for its eradication.