Orbital cellulitis caused by Aeromonas hydrophila developed in a 73-year-old male with a history of myelodysplastic syndrome. He was admitted because of fever, general malaise, pain as well as periorbital swelling in the right eye. Four days later, a yellowish pustule with purulent material was noted over right lower eyelid. Aeromonas hydrophila was isolated from the discharge. After administering intravenous cefuroxime 1,500 mg every 8 hours and topical ofloxacin eye oint, his symptoms subsided gradually. We present the first known case of orbital cellulitis from Aeromonas hydrophila in a patient with myelodysplastic syndrome. In patients with myelodysplastic syndrome, Aeromonas hydrophila should be listed as an important pathogen in any soft tissue infection including eyelid infection. Culture and adequate antimicrobial therapy are recommended, because rapid worsening may result in orbital cellulitis or even septicemia in patients with suppressed immune system.