We report a study of the photoinduced charge transfer in the blends of buckminsterfullerene (C 6 0 ) and thiophene-based copolymers with tunable energy gap. The photoluminescence and steady state photoinduced absorption spectra evidence the electron transfer from the photoexcited copolymer to C 6 0 . The efficiency of the charge transfer depends on the degree of miscibility of the two components which is easily controlled by the copolymer composition.In the blends obtained with a copolymer with an high energy absorption onset, the spectral signatures of the photoinduced hole transfer to the polymer, arising from the selective excitation of the C 6 0 , are also detected.