ABSTRACT: The aim of this study was to identify the conjunctival bacterial flora of healthy horses in Brasilia (Distrito Federal, Brazil), and to evaluate the antimicrobial susceptibility of the isolated strains. We examined 200 eyes of 100 healthy adult horses without any eye problems, belonging to the 1st Regiment of the Cavalry Guard (RCG) of the Brazilian Army in Brasilia. Samples were collected from the inferior conjunctival fornix of both eyes. Drug sensitivity test was performed with the antibiotics gentamicin (10µg), tobramycin (10µg), chloramphenicol (30µg) and ciprofloxacin (5µg). Of the 200 samples collected, 131 (65.5%) were considered positive for bacterial growth. A total of 208 bacterial strains belonging to 19 genera were isolated, where there was prevalence of gram-positive bacteria (65%), with Staphylococcus sp. being the species of greatest incidence. It was observed that 94, 85, 81 and 68% of the isolates were sensitive to ciprofloxacin, gentamicin, chloramphenicol and tobramycin, respectively. These results can guide the empirical selection antimicrobial therapy for infections of the ocular surface of horses, pending the identification of the etiologic agent.