The initial treatment of bacterial ulcers of the cornea should consist of a combination of antibiotics that are effective against the major pathogens in the community. A gram stain may be misleading and therefore may suggest inappropriate therapy. Antibiotic therapy should include subconjunctival injections and concentrated eye drops, but not systemic administration except following perforation. Initially, we use cefazolin and tobramycin or gentamicin. Bacitracin may be substituted as a topical medication. Antibiotic therapy should be changed only if the pathogen is reported to be resistant to initial therapy and if the corneal ulcer continues to worsen.