Bacterial keratitis can lead to severe visual disability and requires prompt diagnosis and treatment. The contact lens wear is an established risk factor for bacterial keratitis. There are several risk factors that predispose the cornea to infection. The dry eyes from Sjogren syndrome, Stevens-Johnson syndrome or vitamin deficiency can result in bacterial keratitis. The entropion and trichiaisis resulting in epithelial defects put the cornea at risk. Some systemic conditions such as chronic alcoholism, severe malnutrition, immunosuppressive drug use, immunodeficiency syndromes and malignancy can impair immune defenses and allow infection by unusual organisms. The chapter in detail discusses about various factors responsible for the cause of bacterial keratitis, the diagnostic techniques, clinical features, and treatments required for bacterial keratitis.