Malignant (invasive) otitis externa is an infection involving the external ear canal, often in elderly diabetic patients, which carries a high morbidity and mortality. It may involve widespread areas of soft tissue around the skull base, and in more advanced cases, may give rise to osteomyelitis and cranial neuropathy. We describe two patients who were treated for malignant otitis externa complicated by destructive osteomyelitis of the temporomandibular joint (TMJ). For both patients, diagnosis was made using magnetic resonance imaging (MRI), and repeat scans were employed during follow-up. Improved scan appearances mirrored improvements in clinical condition in both cases.