An external preparation containing memantine which has less skin irritation and excellent skin permeability, and also, which is suitable for continuous administration for a long period of time. The external preparation contains memantine or a salt thereof, and further contains 0.05 to 1.5% by weight of phosphatidylcholine, 35 to 55% by weight of propylene glycol, 18 to 30% by weight of glycerine, and 22 to 32% by weight of water. The content of water less than 22% by weight may increase skin irritation, and the content of water more than 32% by weight may decrease skin permeability. The content of glycerin less than 18% by weight may increase skin irritation, and the content of glycerin more than 30% by weight may decrease skin permeability.
