Otitis externa can be acute or chronic, diffuse or localised, and can be caused by infection, allergy, irritation or inflammation. It includes all inflammatory conditions of the auricle, external ear canal and outer surface of the tympanic membrane. It is a common problem which constitutes one in six new patient referrals and 30 per cent of people seen in an ear, nose and throat emergency clinic. There are very few good quality trials of treatment for acute otitis externa. Aural toilette may be treatment enough and is necessary for diagnosis and visualisation of the tympanic membrane to exclude perforation. Topical antibacterial medications should be used for the initial treatment of diffuse, uncomplicated acute otitis externa. In difficult cases a broad therapeutic approach may need to be taken. Tri-AdCortyl ointment contains steroid, neomycin and gramicidin and also an antifungal medication. After thorough microsuction, this ointment or similar combinations can be instilled into the ear canal and left until the next appointment.