Malignant tumors of the sinonasal tract are uncommon tumors of the head and neck. Patients often present in the later years of life with unilateral symptoms and potential involvement of nearby structures such as the orbit, brain, or cranial nerves. Presenting symptoms are similar to patients suffering from inflammatory sinonasal disease and thus early diagnosis relies heavily on a high clinical suspicion. There are established risk factors based on exposure to the by-products of woodworking, metal, textile, and leather industries. Sinonasal malignancies are generally divided into those of epithelial origin (squamous cell carcinoma, adenocarcinoma, and adenoid cystic carcinoma) and nonepithelial origin (olfactory neuroblastoma, chondrosarcoma, and mucosal melanoma). Accurate histopathology confirmation and staging of the tumor is critical prior to making treatment decisions. Both computed tomography and magnetic resonance imaging are required to accurately determine the extent of local disease. Treatment is based on multimodality therapy, primarily surgical excision, and postoperative radiotherapy. This article reviews the classification of malignant tumors of the paranasal sinuses, their clinical presentation, relevant diagnostic investigations, and the principals of therapy and management.