We report synthesis, and optical properties, of dihexyl-fluorene-co-3,4-ethylene- dioxythiophene (DHF-co-EDOT) random copolymers obtained from mixture, in various ratios, of the two corresponding dibrominated monomers. Infra-red studies coupled with 1H NMR clearly indicate, as expected, that the amount of each monomer unit in the materials is strongly connected to the feed composition. It clearly appears that even a low 3,4-ethylene- dioxythiophene (EDOT) content, i.e. 15 %, within a poly(dihexyl fluorene) main chain induces significant changes in the electronic properties of the corresponding material, denoted COPO1, compared with the fluorene-based homopolymer. Higher EDOT contents lead to less soluble copolymers which are not or only to a slight extent suitable to investigate their use as luminescent semiconducting ∼-conjugated materials in Organic Light-Emitting Diodes (OLEDs). Green organic light emitting devices based on COPO1, exhibiting no significant spectral evolution, have been demonstrated and showed improved hole-injection properties when compared to the ones using poly(dihexyl fluorene). The use of an additional PEDOT- PSS layer on the ITO anode has also been investigated leading to improved operating lifetime.