Malignant otitis externas is an uncommon potentially fatal infectien ef the external ear caused by Pseudomona aeruginosa. It occurs usually in elderly diabetics and is followed by rapid invasion of the deep perisuricular tissue and bone leading to osteomyelitis. We Present such a patient whose disease persisted inspite of twe months antibiotic therapy until the concomitant of hyperbaric oxygen therapy was given over a period ef four weeks. Cemplete recovery followed.