Sinonasal tumors (SNTs) are rare epithelial and mesenchymal tumors of the nasal cavity and paranasal sinuses. The management strategy is complicated by proximity to critical neurovascular structures. Endoscopic endonasal surgery (EES) is an alternative to transfacial approaches. This study assessed the feasibility and outcome of endoscopic resection of SNTs. This prospective study included various pathological types of SNTs. Preoperative evaluation and staging were done by endoscopic biopsy, CT, or MRI. All cases were managed by EES under general anesthesia. Data collected included outcome and intra- and postoperative complications. This series included 22 patients (11 males) with a median age of 33.5 years (range: 5-65 years). Five patients were children. The mean operative time was 2.1±0.8 hours. The procedure was successful in all but one case. There were no intraoperative complications, but two patients developed postoperative bleeding and CSF leak. Definitive diagnosis was possible in 19 patients revealing seven benign and twelve malignant lesions [adenocarcinoma (n=3), olfactory neuroblastoma (n=3), rhabdomyosarcoma (n=2), and one case of Ewing sarcoma, chondrosarcoma, chordoma, and SCC]. Eight patients (36.4%) received neoadjuvant chemotherapy. Six patients developed local recurrence (27.3%) within the first 14 months after surgery. Two patients died due to local recurrence, one with left ethmoidal embryonal rhabdomyosarcoma and the other had recurrent olfactory neuroblastoma. Endoscopic endonasal resection is a feasible and safe procedure in managing different types of benign and malignant tumors with a single failure (4.5%). Five recurrences and two deaths were recorded in the malignant lesions.