We investigate the spin-flip process through double quantum dots coupled to two half-metallic ferromagnetic leads in series. By means of the slave-boson mean-field approximation, we calculate the density of states in the Kondo regime for two different configurations of the leads. It is found that the transport shows some remarkable properties depending on the spin-flip strength. These effects may be useful in exploiting the role of electronic correlation in spintronics. We investigate the spin-flip process through double quantum dots coupled to two half-metallic ferromagnetic leads in series. By means of the slave-boson mean-field approximation, we calculate the density of states in the Kondo regime for two different configurations of the leads. It is found that the transport shows some remarkable properties depending on the spin-flip strength. These effects may be useful in exploiting the role of electronic correlation in spintronics.