Atomic layer deposition (ALD) has been established as a powerful method for the growth of very thin and conformal films to be used in ultra-scaled conventional and novel microelectronic devices. We report the most recent advancements in the field of ALD of rare-earth-based oxides to be implemented as active dielectrics. The review is balanced between the development of new ALD processes and the assessment and the discussion of fundamental scientific issues related to the structural, chemical and electrical properties of thin films of rare-earth-based oxides. The deposition process of binary lanthanide oxides is critically reviewed focusing on the first (La) and last (Lu) element of the series. Concomitantly, the integration of rare earth elements as dopant atoms in HfO 2 and ZrO 2 is also systematically reported. A final overview is dedicated to the results obtained by ALD of more innovative lanthanum-based …