In the present work, rotational friction welding of an aluminium rare-earth based high creep-resistance magnesium (Mg) alloy AE42-HP was investigated, using the continuous drive method. Analyses of the welding parameters and their influence on the joint formation as well as temperature measurements were carried out within this context. In addition, metallurgical characterization using light and scanning electron microscopes (SEM) with additional grain size measurements were performed, to obtain a better understanding of the mechanisms involved on the joint formation. Tensile tests were also performed to mechanically evaluate friction welding as an alternative for joining high creep-resistance Mg alloys. Preliminary results showed a good reproducibility and reliability of the friction welding system. Moreover, it was proved that the process can produce sound welds characterized by the formation of a refined dynamically recrystallized microstructure with a complete rupture of the typical "as cast" base material (BM) lamellae microstructure along the recrystallized zone. Average grain size varies from 4.8 to 11.1 μm within the recrystallized zone, which generated joints with tensile strengths comparable to those of the BM.