The authors present a case of optic nerve cysticercosis in a 32-year-old patient who presented with sudden blurring of vision in the left eye and a transient visual improvement on systemic steroids. The ocular findings were unremarkable other than a relative afferent pupillary defect (RAPD). An ultrasound of the orbit, CT and MRI scans revealed a cystic lesion in the orbital portion of the optic nerve close to the eyeball. A presumed diagnosis of optic nerve cysticercosis was made on the basis of imaging and a positive serum ELISA. The patient improved dramatically on a 4-week therapeutic trial of albendazole and oral steroids. The post-treatment ultrasound and CT scan showed an involution of the cyst with some residual thickening of the optic nerve.