Provided are a single-layered hydraulic transfer printing base film, including 1.5 to 15 parts by mass of a plate or needle filler with an average particle diameter of from 2 to 14 μm and an aspect ratio of from 4 to 60 based on 100 parts by mass of polyvinyl alcohol and a method of producing a hydraulic transfer printing base film, including forming a film using a liquid containing 1.5 to 15 parts by mass of a plate or needle filler with an average particle diameter of from 2 to 14 μm and an aspect ratio of from 4 to 60 based on 100 parts by mass of polyvinyl alcohol. A hydraulic transfer printing base film that is not easily broken when fed from a roll and a method of producing the base film are thus provided.