This series describes five dogs with nasal polyps diagnosed between 2000 and 2011. Clinical signs included reverse sneezing, nasal discharge, epistaxsis, and stertor when breathing. Computerised tomographic findings included soft tissue mass, turbinate destruction, extension through the bony nasal septum and partial lysis of bones surrounding the nasal cavity. Three dogs were treated by dorsal rhinotomy, one dog was treated by ventral rhinotomy, and in one dog the polyp tissue was removed during nasal flushing. Three dogs have no clinical signs of nasal disease. One dog had confirmed recurrence of nasal polyps and was successfully treated with megavoltage radiation. One dog had recurrent nasal disease eight months after dorsal rhinotomy. Nasal polyps are a possible cause of nasal disease in dogs with nasal discharge, epistaxsis and stertor, and a differential diagnosis for dogs with extensive soft tissue lesions of the nasal cavities on computerised tomography. Nasal polyps can be treated successfully by rhinotomy in some cases but may reoccur.