A hybrid material containing maghemite and polyaniline (PAni) doped with dodecylbenzenesulfonic acid (DBSA) was prepared through in situ polymerization in aqueous medium. The pure maghemite powder presented average particle diameter of 10 nm and magnetization force of 14 mN. The obtained maghemite/PAni hybrid material also presented nanometric dimensions, associated with reasonable electrical conductivity (260 times larger than the electrical conductivity of the pure maghemite) and about 60% of the original magnetic force. Additionally, the electrical conductivity of the hybrid powder showed significant sensitivity to changes of the magnetic field, indicating that these materials can be useful as magnetic field sensors.