A 47-year-old woman with a 3 month's history of progressive visual loss in her right eye presented with right fundus normal but with marked papilledema on the left. Magnetic resonance imaging (MRI) revealed a large right 'en plaque' meningioma which was successfully removed via a pterional craniotomy. The case outlines that unilateral papilledema offers little information concerning tumor localization, and may represent a 'false' localizing sign.