This entry is adapted from 10.3390/molecules28155739. Nanoparticles are defined as matter that has at least one dimension between 1 and 100 nm, and that generally has different properties from its bulk. Phosphorus dendrimers are hyperbranched macromolecules synthesized step-by-step, bearing a phosphorus atom at each branching point. Such type of dendrimers are suitable for the synthesis of diverse types of metal nanoparticles from organometallic precursors.