Aims: To present a rare case of sinonasal glomangiopericytoma and describe the clinical presentation, imaging findings, operative assessment, and planned surgical management aimed at complete excision and long-term surveillance. Methodology: Sinonasal glomangiopericytoma accounts for <0.5% of sinonasal tumours, typically indolent but with a risk of late local recurrence. A 56-year-old woman with thalassemia minor presented with six months of intermittent right epistaxis. Nasal endoscopy showed a vascular lesion on the posterior right septum. CT demonstrated polypoidal thickening in the right nasal cavity. MRI revealed a 17 mm avidly enhancing septal lesion without orbital or intracranial extension. PET showed mild, symmetric FDG uptake (SUVmax 2.8), consistent with the low metabolic activity typical of this tumour. No nodal or distant disease was identified. Endoscopic biopsy confirmed sinonasal glomangiopericytoma. Results: Intraoperatively, a sessile vascular lesion was identified on the posterosuperior right septum, with subtle induration on the contralateral side suggesting early cross-septal involvement. The skull base was intact. Histology demonstrated classic features of glomangiopericytoma without necrosis, bone invasion, or elevated mitotic activity. Multidisciplinary review recommended curative surgery. The patient is planned for an endoscopic posterior septectomy and sinus surgery to achieve circumferential clearance, fully visualise both septal surfaces, and support long-term surveillance given recurrence potential. Conclusion: Sinonasal glomangiopericytoma is a rare vascular tumour that may present with isolated epistaxis. CT, MRI, and PET imaging help define extent and exclude metastatic spread, while endoscopic evaluation and histopathology confirm diagnosis. Posterior septectomy offers a safe, margin-focused approach for septal lesions and provides excellent access for durable postoperative surveillance.