Our hypothesis is that coughing horses have airway inflammation. Fifty horses – 36 coughing (Co Group)and 14 control (C Group) – of different gender, age, and function were evaluated. Physical and endoscopicexaminations, and cytological analyses of tracheal wash (TW) and bronchoalveolar lavage (BAL) fluids wereundertaken. Higher grades of tracheal mucus were observed in coughing horses. TW fluid neutrophil countwas higher (46.4% ± 30.8% vs. 19.5% ± 22.9%, p=0.003) in the Co group than the C group. In BAL fluid,neutrophil count was higher in the Co group than in the C group (30.3% ± 27.3% vs. 5.0% ± 4.2%, p=0.001,respectively). BAL fluid cytological profile compatible with inflammatory airway disease (IAD), recurrentairway obstruction (RAO), and normal were evidenced in 14 (38.9%), 17 (47.2%), and 5 (13.9%) of theevaluated coughing horses. IAD was diagnosed in 6 horses of the C group. Cough is a clinical sign of airwayinflammation in horses.