PIP: Ophthalmia neonatorum is defined as any conjunctivitis with discharge from the eyes during the first 28 days of life. Its etiology may be gonococcal or nongonococcal, Chlamydia trachomatis being the most important cause in the latter group. The risks of gonococcal and chlamydial ophthalmia in infants born to infected mothers may be up to 30% and 50%, respectively. Gonococcal ophthalmia, if untreated, may progress rapidly to corneal ulceration, perforation, and eventually blindness. Chlamydial ophthalmia is generally milder. Ophthalmia neonatorum can be prevented by: 1) the parents' avoidance of risky sexual behavior that could lead to sexually transmitted infections; 2) routine screening for chlamydia and gonococcal infections in antenatal clinics followed by appropriate treatment; and 3) disinfection of the infant's conjunctivae at birth by: a) use of 1% aqueous silver nitrate solution into each conjunctival sac; b) instillation of benzyl penicillin solution into the infant's eyes; or c) use of tetracycline 1% or erythromycin 0.5% eye ointment. The safety and efficacy of povidone-iodine ophthalmic solution to prevent ophthalmia neonatorum was evaluated by enrolling 3117 infants born at the Presbyterian Church Hospital in Kikuyu, Kenya, from March 1991 to August 1993. The infants received one of the ophthalmic preparations: a drop of 1% silver nitrate ophthalmic solution or a l cm strip of 0.5% erythromycin ophthalmic ointment, or a drop of 2.5% povidone-iodine solution. Povidone-iodine was significantly more effective than silver nitrate and erythromycin in preventing ophthalmia neonatorum overall, and especially in preventing chlamydia ophthalmia. The incidence of N. gonorrhea and Staphylococcus aureus infections was, however, similar in the three groups. Povidone-iodine deserves serious consideration in prophylaxis against ophthalmia neonatorum in developing countries because of its efficacy, low cost, and easy availability.