A method of producing a transdermal absorption sheet includes: filling needle-like recessed portions on a mold having the needle-like recessed portions with a polymer solution; drying the filled polymer solution to form a polymer layer; and peeling off the polymer layer, wherein, in drying the polymer solution, low rate drying conditions are set in a concentration range in which an average solid content concentration of the polymer solution is 70 wt % to 80 wt %. When a constant drying rate of water is used as an index, in the concentration range in which the average solid content concentration of the polymer solution is 70 wt % to 80 wt %, and the constant drying rate is lower than a maximum value of a constant drying rate under a drying condition where the average solid content concentration of the polymer solution is less than 70 wt % and more than 80 wt %.