Propentofylline is a methylxanthine derivative with bronchodilating actions similar to those of theophylline. Nineteen cats with bronchial disease were enrolled in this study. All cats received a low dose of prednisolone; 10 of the cats additionally received propentofylline. Propentofylline-treated cats significantly improved in their auscultation scores, respiratory pattern scores, and radiological bronchial markings score over the observation period, and they coughed less and slept less at the end of the study. No significant changes were noted in the control group. This study provides evidence that a combination therapy with prednisolone and propentofylline in cats with bronchial disease might be superior over monotherapy with prednisolone.