A previously healthy 32-year-old Caucasian female presented with sudden-onset horizontal diplopia following a paroxysm of coughing. She had recently sustained a pubic ramus fracture during an innocuous fall and had also noted a firm lump developing at the right side of her forehead. On examination, she had a right fronto-temporal mass. Visual acuities were 6/6 bilaterally. There was reduced abduction of the right eye, bilateral white, granular corneal opacities and evidence of bilateral optic disc swelling. Haematological investigations revealed normocytic anaemia, hypercalcaemia and raised erythrocyte sedimentation rate (ESR). CT showed lytic foci throughout the skull, ribs, scapulae, spine, pelvis and upper femora. Serum protein electrophoresis revealed immunoglobulin D (IgD)-kappa paraproteinaemia; urine electrophoresis showed free light chain kappa and bone marrow biopsy demonstrated 87% plasma cells. A diagnosis of IgD multiple myeloma was made, with subsequent chemotherapeutic treatment and eventual autologous stem cell transplant resulting in resolution of neuro-ophthalmic manifestations and prolonged disease remission.