This case report describes an incident of pneumothorax in 4-month old male German Shorthaired Pointer caused by a grass awn. The patient was brought to the Small Animal Clinic of the Faculty of Veterinary Medicine at Trakia University, Stara Zagora, Bulgaria with respiratory distress and anxiety. Tachypnea, cyanotic mucous membranes and tachycardia were observed during physical examination. Abnormal collection of air in the pleural space between the lung and the chest was observed radiographically. A diagnosis of primary spontaneous closed pneumothorax was made based on these findings. Later pathoanatomical findings showed the presence of the grass awn that had penetrated through the skin.