INTRODUCTION: Malignant otitis externa is a life-threatening infection of the skull base. Its presentation is not always typical. CASE REPORTS: We report three cases of malignant otitis externa which illustrate the diversity of its clinical manifestations and the difficulties in its diagnosis. DISCUSSION: The perception of malignant otitis externa as an infection caused by Pseudomonas aeruginosa in diabetic patients is not always correct. The adoption of diagnostic criteria could be helpful in identifying atypical cases.