Malignant sinonasal tumors account 3% of all aerodigestive tract malignancies. 5th and 6th decade of life is the most common age of presentation with male to female ratio as 2:1. Maxillary sinus (55%) and nasal cavity (35%) is the most common site for origin of tumors. The most common histological type of tumor is squamous cell carcinoma followed by adenocarcinoma. Smoking, aflatoxin, and heavy metal like chromium, nickel, and polycyclic hydrocarbons are etiological factors. Occupational exposure to hard and soft wood increases chances of adenocarcinoma. This chapter covers the clinical presentation, local examination, imaging, biopsy, classification, management, and staging. The presenting symptom will be depending on the area of involvement. Nasal obstruction and bleeding are the leading symptoms. Both contrast-enhanced computed tomography (CECT) and contrast enhanced magnetic resonance imaging (CEMRI) are required for accurate evaluation and staging purposes.