The clinical signs associated with intramural tracheal obstructions in two horses and a donkey were respiratory distress and coughing, which were aggravated by exercise and excitement. The obstructions were at the level of the thoracic inlet and consisted either of flattening of the cartilage rings in the dorsoventral plane or of cartilage rings having a scroll-like conformation. They appeared to be developmental in origin and to have been present for a considerable time before the onset of clinical signs. Endoscopy and radiography were helpful in the diagnosis of the condition.