A six-year-old, male, castrated European shorthair cat was presented due to a lifelong history of sneezing, nasal discharge, open-mouth breathing, stertor and vestibular problems. Clinical examination showed absence of airflow through the nostrils. Computed tomography of the head revealed an infiltrative soft tissue attenuating mass in the left nasal cavity, nasopharynx and the left frontal sinus. All of these locations could be successfully accessed through ventral rhinotomy and the mass was completely removed. Histological examination identified it as an inflammatory polyp. All respiratory and neurological symptoms disappeared, and two-and-a-half years after surgery, the cat was still without complaints.