NHC‐ligated Pt nanoparticles were studied with regards to steric bulk of the ligands and their influence on NP size and catalytic properties. Bulky aryl groups at the N‐atoms gave small NPs of roughly 65 atoms, whereas small methyl groups gave larger NPs of around 260 atoms both with high ligand coverage, 12 and 70 ligands, respectively. Undecyl chains on the NHC ligands make the nanoparticles highly soluble and allowed for their use as catalysts in solution. Hydroboration of alkynes was observed for the first time with soluble NPs, but surprisingly only the bulky‐ligand‐containing Pt NPs were active. More information can be found in the Full Paper by F. Glorius, B. Chaudret and P. W. N. M. van Leeuwen et al. on page 12779.