Extramedullary plasmacytoma is a rare malignant plasma cell tumour. We report an extremely aggressive case of extramedullary plasmacytoma of the right maxillary sinus, which had metastasised to the brain and rib. A 56-year-old man presented with recurrent epistaxis and acute anaemia. Nasendoscopy revealed a medialised medial wall of the right maxilla and a mass occupying the whole nasopharynx. Magnetic resonance imaging revealed a right maxillary tumour with extension to the ipsilateral nasal cavity, nasopharynx, right sphenoid and ethmoidal sinuses. There was an extra-axial brain metastasis. There were metastases to the right parietal region and left eighth rib. Histopathology examination of the maxillary mass revealed abundant plasma cells with kappa-chain restriction. He was planned for four cycles of chemotherapy. Unfortunately, in view of the advanced stage of disease, he succumbed to his disease during the first cycle of chemotherapy.