Objective: Malignant external otitis (MEO) is an aggressive infection, primarily affecting elderly diabetic patients. It begins in the external ear canal and spreads to adjacent structures. This study investigated the clinical characteristics of patients diagnosed and treated for MEO and analyzed factors affecting patient outcomes., Study Design: Historical cohort., Setting: Tertiary medical center., Methods: Medical records of all patients diagnosed and treated for MEO from 1990 to 2013, were retrospectively reviewed. Clinical features, laboratory, imaging and outcomes were analyzed., Results: 88 patients were included, mean age was 73±11.5years, 61 (69%) were male. Of these, 75% had diabetes. Mean follow-up was 60months. The most common presenting symptoms were otalgia (89%), external ear canal edema (86%) and otorrhea (84%). Pseudomonas aeruginosa was isolated in 61% of ear cultures. All patients were treated with antibiotics, 22% had surgery and 8% hyperbaric oxygen. Overall survival rate was 38% in 5years, with disease specific mortality 14%. DM, facial nerve palsy, positive CT scan and age above 70 were found to correlate and predict disease-specific mortality., Conclusions: MEO carries a grave prognosis. The presence of two or more of the following features, DM, facial nerve palsy, positive CT scan and age above 70, predicts poor outcome, and highlights the need for prolonged, vigorous treatment., (Copyright © 2016 Elsevier Inc. All rights reserved.)