Objective: Determine the initial therapy choices for newly-diagnosed episodes of acute otitis externa (AOE) in the Louisiana Medicaid population. Methods: Louisiana Medicaid claims were retrospectively analyzed for the period of January 1, 2004, through December 31, 2005. Recipients aged 1-64 who had a paid medical claim (index claim) with a diagnosis of AOE (ICD-9-CM codes 380.10 or 380.12) were identified in the dataset. Additional inclusion criteria included a paid pharmacy claim for an oral antibiotic or an otic preparation within five days of the index claim. Recipients were excluded if they had multiple insurances, dual antibiotic or additional numbing agent therapy, co-morbid conditions, or concomitant infections. Recipients were also excluded if they had a medical claim for an AOE diagnosis or a prescription claim for an antibiotic or steroid during a 30-day washout period prior to the index claim. The initial pharmacy claims were grouped into five drug categories, and physicians were grouped as pediatricians, general practitioners, and other physicians. Results: There were 32,059 recipients who met the initial eligibility criteria. After exclusions, a sample of 8090 recipients remained. The initial drug therapies prescribed for these recipients included topical fluoroquinolone antibiotic-steroid combination drugs (n=2290), topical non-fluoroquinolone antibiotic-steroid combination drugs (n=2006), otic antibiotics (n=1,406), oral antibiotics (n=1507), and other otic preparations including acidifying agents, numbing agents, and combinations (n=881). Conclusion: Topical fluoroquinolone or non-fluoroquinolone antibiotic-steroid combinations were the most frequently prescribed medications, together representing 53% of the initial therapy choices for AOE. These were followed by oral antibiotics (19%), otic antibiotics (17%), and other otic preparations (11%). Pediatricians prescribed fluoroquinolone containing combinations more frequently than general practitioners, who tended to prescribe non-fluoroquinolone containing combinations most frequently.