Surface resistivity (ρs) of polyurethane (PU) films is reduced from 2.1 × 1012 to 9.4 × 1010 ohm sq−1 by addition of 1‐butyl‐3‐methylimidazolium bis(trifluoromethanesulfonyl)imide ([C4mim][Tf2N]) for only 10 ppm. Addition of [Tf2N]‐type ionic liquids (ILs) for 1 000 ppm leads to the reduction of not only ρs from 1012 to 109 ohm sq−1 but also volume resistivity (ρv) from 109 to 107 ohm cm, suggesting that the ILs are uniformly incorporated into the PU films. These PU films have ρs in the order of 109 ohm sq−1 even after methanol washing. The antistatic effects are attributed to ionic conductivity of the PU films, which is achieved by low glass transition temperatures of both PU films and [Tf2N]‐type ILs. These results suggest that [Tf2N]‐type ILs are excellent antistatic agents for PUs.