Acute otitis externa is an infection of the outer ear canal that can occur at any age and is diagnosed by symptoms and examination findings. The aims of our study were to understand the seasonal frequency of acute otitis externa and to determine the susceptibility of causative bacteria to ciprofloxacin. Discharge samples were collected from the external ear canals of 76 patients diagnosed with acute otitis externa. The samples were evaluated and culture-antibiogram results were compiled. Routine microbiological methods were used for the reproduction of clinical material as bacterial and fungal cultures. The 76 enrolled patients were 18–80 years old (mean 41.6 years). Acute otitis externa occurred most frequently during summer, especially in July. Culture results revealed Pseudomonas aeruginosa growth in 30 cases (39.4%), Staphylococcus aureus in 18 cases (23.6%), and Serratia spp. in 5 cases (6.5%), while fungal growth was observed in 10 cases (13.1%). The antibiogram analyses determined ciprofloxacin resistance in P. aeruginosa in 13 patients (43.3%) and in S. aureus in 6 patients (33.3%). Acute otitis externa should be treated with antibiotics in accordance with culture antibiogram results, while keeping in mind that bacterial causes could be ciprofloxacin resistant.