Lead halide perovskite nanocrystals have been widely studied in recent years due to their huge application potential as a cost-effective UV-VIS semiconductor. In this work we prepare and study Yb-doped all-inorganic perovskite nanocrystals (IP-NCs). Introduction of rare earth (RE) ions is a popular way to modify photonic properties of semiconductors, due to the RE’s sharp electronic transitions in VIS-NIR. However, because of the small absorption cross-sections, for practical applications of RE-doped materials, there is an urgent need for efficient sensitization. Perovskites are a natural candidate to host RE dopants, providing strong absorption and high resistance to crystal defects. Here we explore several synthesis techniques of RE-doped IP-NCs, characterizing them by their optical properties. In particular, we show NIR photoluminescence quantum yields in excess of 100%, and discuss the excitation mechanism of Yb ions, their photoluminescence quantum yield and its limits. Keeping in mind applications such as down-conversion layers for solar cells, the application potential of these doped perovskites looks very promising.