Carrier dynamics properties in swollen poly(octylthiophene) gels are investigated via their radiative and non-radiative recombination rates (Wr and Wnr respectively) as a function of their swelling ratio (Q). Photoluminescence decay time (τ, in the picosecond range) and luminescence quantum efficiency (QE) are found to strongly increase with Q. This implies that Wr increases and Wnr decreases as Q increases; such a result cannot be understood if one accounts only for the well-known dilution effect observed for organic dyes. Our interpretation is that the enhanced carrier transport due to the increase of interchain interactions observed upon deswelling induces a separation of carriers. Then, these latter present an increased probability to find non-radiative traps. Variation of the conductivity versus Q in doped gels is also discussed.