Otitis externa means mainly inflammation of the external ear canal distal to the tympanic membrane. Clinical, microscopical and bacteriological examination of 687 cats were examined throughout the present study From April 2012 to December 2015 before and after treatment, aged between 33 days and 2.8 years, brought in for their first veterinary examination to faculty of veterinary medicine, Cairo university hospital and private veterinary clinics. They were suffering from ear disease (otitis externa) with different discharges. They were classified into two groups, first group was mange group (632 cases out of 687, 92%) classified into 507 cases out of 687 (73.8%) with blackish exudates only, 113 cases out of 687 (16.4%) with blackish exudates and oozes pus, 9 cases out of 687 (1.3%) with blackish exudates and ear hematoma, 3 cases out of 687 (0.4%) with blackish exudates, oozes pus and head tilt. Second group consisted of negative mange group (55 cases, 8.1%) with purulent discharge and fetid odor. bacteriological examination revealed Staph. aureus 19 out 20 (95%) and Corynebacterium spp. | out of 20 (5%) in the group | before treatment. While group 2 revealed Staph. aureus 8 out 10 (80%) and Corynebacterium spp. 2 out of 10 (20%) before treatment. After topical treatment, samples from group 1 showed negative results except for Corynebacterium (19 out of 20, 95%), While group 2 showed negative results (10 out of 10, 100%). Antibiotic sensitivity testing displayed high sensitivity to rifampicin and clindamycin except resistant Corynebacterium spp. in the first group which prescribed to the owners. The present study concluded that Otodectes cyanotis was the most common cause of otitis externa. Treatment by deltamethrin and povidone iodine after ear cleaning was effective, faster and cheaper than other drugs.