A ketoprofen-containing aqueous patch is provided in which not only operational efficiency in producing is improved, but also the aqueous patch has excellent storage stability and transdermal absorption of ketoprofen. The ketoprofen lysine salt-containing aqueous patch includes a backing layer and an adhesive (paste) layer laminated thereon. The aqueous patch includes as a main active ingredient a ketoprofen lysine salt completely dissolved in a paste including not glycerin but a polyethylene glycol having an average molecular weight of 1000 or less. In the ketoprofen lysine salt-containing aqueous patch, the polyethylene glycol having an average molecular weight of 1000 or less is one or more polyethylene glycols selected from the group consisting of Polyethylene glycol 200, Polyethylene glycol 400, Polyethylene glycol 600, and Polyethylene glycol 1000.