In order to produce magnetic microparticles (agglomerates), magnetite (Fe3O4) particles were synthesized using coprecipitation of FeSO4 center dot 7H(2)O and FeCl3 center dot 6H(2)O with the presence of poly (methacrylic acid) (PMAA) in aqueous solution.. Transmission electron microscopy (TEM), X-ray diffraction, and vibrating sample magnetometry (VSM) methods were used to characterize the PMAA coated superparamagnetic agglomerates. The influences of various processing parameters such as the process temperature, PMAA content, and the addition of surfactant on the agglomerate size and size distribution of produced magnetic microparticles were investigated. The particle size and size distribution characteristics, (the volume weighted mean size (1)[4,31, surface weighted mean size D[3,2], the geometric standard deviation, and span value) of the magnetic agglomerates were determined using the laser diffraction technique. The PMAA coated magnetic agglomerates with surface weighted mean sizes ranging from 1.5 to 3 mu m were produced successfully. (C) 2009 Elsevier Ltd. All rights reserved.