Chiral photonics is an emerging field which deals with enantioselective light–matter interactions, offering numerous exciting applications. Two main approaches to enhancing enantioselective interactions are currently under extensive study: 1) structuring light itself, and 2) developing materials with gigantic optical activity. Both are required to realize the full potential of this emerging field. Here, the intensity-dependent optical activity of a chiral polyfluorene film that has been studied by using open- and closed-aperture z-scan techniques with ∼775 nm and ∼160 fs laser pulses is reported. For a film of ∼20 μm thickness, the measured two-photon absorption coefficients are 1.24 and 1.49 cm GW-1, respectively, and the nonlinear refractive indices are 8.74 × 10−5 and 1.38 × 10−4 cm2 GW-1 for right and left circularly polarized laser beams, respectively. The nonlinear optical activity of pure, undoped polyfluorene is the highest reported so far.