Pseudomonas aeruginosa is a devastating agent of fulminant keratitis in contact lens-wearers, immunosuppressive patients, and refractive surgery patients which may lead to substantial loss of vision, and in severe cases, blindness. In this case report, a 30-year-old diabetic contact lens wearer who had history of sleeping with lenses and prolonged use of the same contact lens presented with multiple foci of keratitis in each eye. No pathogen was detected from corneal scrapings, but the contact lenses and the contact lens case were culture positive for Pseudomonas aeruginosa. The keratitis was only partially responsive to topical fortified ceftazidime, topical fortified vancomycin, and topical fluconazole. A decision was made to switch to topical imipenem-cilastatin due to the multiple risk factors, including diabetes, contact lens overuse, and bilateral multifocal corneal involvement, after which the keratitis resolved. Topical imipenem-cilastatin may be a successful alternative treatment in patients with Pseudomonas keratitis who do not respond to conventional antibiotic therapy.