In this study, the magnetic properties of iron-based coatings obtained by HVOF thermal spraying were investigated. These properties were correlated to alloy type, heat treating temperature and coating thickness using artificial neural network method. Among coating characteristics, porosity is regarded as an influential parameter on the magnetic properties. Therefore, the role of the microstructure was particularly emphasized in this study. Magnetic properties, especially coercivity, showed a weak decrease with the addition of alloying elements. However, these properties remained nearly unchanged at high temperatures and for large coating thicknesses. Porosities are regarded as defects anchoring Bloch walls and consequently promoting an increase of coercivity.