Preparation of magnetic latexes using styrene as monomer was carried out via miniemulsion polymerization. Magnetite (Fe3O4), with an average size of 12nm was used as magnetic particles. An organic phase is prepared dispersing the magnetite in styrene where bis(2-ethyl, hexyl) sulphosuccinate (AOT) is used as dispersant of the particles. The dispersion is miniemulsified in water using Cethyltrimethylammonium bromide (CTAB) as second emulsifier forming a stable emulsion. The miniemulsion polymerization was carried out at 60degrees C and was initiated with 2,2 Azo-bis-iso-butyronitrile (AIBN). The latexes obtained were characterized by X-ray diffraction, Magnetometry and Transmission Electronic Microscopy.