Designs of switched-current fractional-order filters are presented in this paper. The derivation of the filters is performed through a transposition of the Functional Block Diagram of the continuous-time prototype filter into discrete-time domain using the bilinear s-to-z transformation. Fully differential bilinear integrators have been employed in order to facilitate the realization of the required current inversions. The correct operation of the proposed design method has been verified through simulation in the cases of (1+a) and (3+a) order lowpass filters.