Induction welding is a fusion bonding technique relying on the application of an oscillating magnetic field to generate heat at the joining interface. Heat dissipation occurs in electrically-conductive materials through induced eddy currents and Joule losses, or in magnetic materials through hysteresis losses. In the second case, the heating element is called a susceptor and is made of ferromagnetic microparticles dispersed in a thermoplastic polymer. A methodology to select magnetic particles suitable with the polymer to be welded is presented in this study. The applied magnetic field, the polymer thermal and physical properties, and the particles magnetic, thermal, and physical properties must be characterized to predict the heating rate of a given susceptor. A case study is conducted to assess the validity of the method. Three materials – iron (Fe), nickel (Ni) and magnetite (Fe3O4) – are evaluated to act as susceptors in polypropylene (PP). Following the proposed steps, their heating rates are predicted at two different particles volume fractions (5% and 10%vol). Fe is not suitable because of its weak magnetic properties. Ni exhibits predicted heating rate around 50% higher than Fe3O4. Samples are then produced by mixing the magnetic particles with PP. Their experimental heating is measured and compared to the predictions. Results show good agreement with the predictions, highlighting that Ni is the most suitable susceptor material to weld PP by induction, as predicted. To verify the welding capability of the Ni/PP susceptor, single lap-shear samples are produced. Adherents of PP are welded by induction under varying welding force and welding speed, without doing any surface preparation. The shear strength of the joint is mechanically characterized. In one of the four investigated welding configurations, all the specimens broke into the PP adherent, showing the successful welding of the parts.