Infectious conjunctivitis of the newborn is caused by a wide variety of microorganisms. The ocular findings may be part of a widespread systemic infection. Clinical presentations are not diagnostic of the cause, and a microbiologic work-up with cytology, cultures, and microbial sensitivities is mandatory. The selection of specific antimicrobial therapy is based on the findings of laboratory studies. Prophylaxis with silver nitrate solution, 1.0% tetracycline, or 0.05% erythromycin ointment is effective for the prevention of gonococcal and chlamydial conjunctivitis in the newborn.