Conductive thermoplastic blends of polystyrene and polyaniline doped with dodecylbenzene sulfonic acid, DBSA and polystyrene sulfonic acid were prepared in an internal mixer. We used a block copolymer of styrene and butadiene as compatibilizer. Different formulations were tested according to a statistical response surface method. The electrical conductivity and the microwave radiation absorbing properties of the blends were evaluated. The concentration of the compatibilizer and polyaniline and the blend film thickness affect the attenuation properties of the materials.