Poul Hansen started with wrestling in 1907 and concentrated on Greco-Roman. After World War I he became one of the top Danish wrestlers in the light-heavy- and heavyweight classes. His greatest success came with the silver medal in the 1920 Olympic Games after five consecutive wins in the heavyweight division. At the 1922 World Championships Hansen finished in fourth place as a heavyweight. At the 1924 Paris Olympics he returned in the heavyweight division but finished only ninth. Hansen did not participate in any subsequent international championships. However, in the late 1920s Hansen still competed internationally as a member of the Danish national team.