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 (H(2)PtCl(6)(.)6H(2)O), (B) micellization in acidic molecular solutions of block copolymers induced by interaction of the protonated amino groups with the PtCl62- ions, and (C) incorporation of metal species in pH-induced micelles. The latter method leads to well-defined metalated micelles of 22-25 mn 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.