Micelle transformations upon metalation (i.e., incorporation of metal compounds and metal nanoparticle formation) in poly(methoxy hexa(ethylene glycol) methacrylate)-block-poly((2-(diethylamino)ethyl methacrylate)), PHEGMA-b-PDEAEMA, solutions have been studied using transmission electron microscopy (TEM) and photon correlation spectroscopy (PCS). Three different methods for the formation of metalated micelles are compared:  (A) dissolution of the block copolymers in pure water followed by incorporation of platinic acid (H₂PtCl₆·6H₂O), (B) micellization in acidic molecular solutions of block copolymers induced by interaction of the protonated amino groups with the PtCl₆^2- ions, and (C) incorporation of metal species in pH-induced micelles. The latter method leads to well-defined metalated micelles of 22−25 nm diameter containing nanoparticles with diameters of 1.3−1.5 nm. No nanoparticle aggregation is observed. Good agreement is obtained for the sizes of the platinic acid-containing micelles assessed by TEM and PCS.