This report reviews the role of palladium dendrimers in catalysis as (a) soluble macromolecules for the support of catalysts, that are separable by nanofiltration techniques; (b) ligand-modifiers that can create specific metal nanoenvironments and tune the solubility of the catalyst; (c) spacers for the support of molecular catalysts that can proportionate a more homogeneous-like environment to the supported catalytic sites; and (d) precursors for the synthesis of mono- and bimetallic nanoparticles of controlled size and narrow size distribution. Some examples of catalysis with related metal systems, such as star-shaped molecules or hyperbranched polymers, are also given.