An external patch containing diclofenac hydroxyethylpyrrolidine prepared by laminating an adhesive layer on a backing, wherein said adhesive layer is characterized by comprising 5-50% by weight of styrene•isoprene•styrene block copolymer, 20-50% by weight of a tackifier resin, 5-70% by weight of a softening agent, and 0.5-20% by weight of one or more solubilizers selected from N-methyl-2-pyrrolidone, propylene glycol and dimethyl sulfoxide as essential ingredients, and 0.5-20% by weight of diclofenac hydroxyethylpyrrolidine as an active ingredient. The patch has excellent transdermal absorption, less skin-irritation and excellent stability of the drug.
