Bacterial infections are by far the most common cause of infectious keratitisInfectious keratitis in high-income countries. The clinical appearance can vary widely depending on the type and species of bacteriaBacteria, ranging from small superficial infiltrates to necrotizing forms. The multiple classes of available antibioticsAntibiotics render the therapeutic scope varied and complex, especially before pathogen specification and antibiotic sensitivity testingAntibiotic sensitivity testing. This chapter focuses on the clinical, diagnostic and therapeutic approaches to bacterial keratitisKeratitis.