AbstractTri‐ and pentablock amphiphilic copolymers containing hydrophobic poly(D,L‐lactide) block(s) and hydrophilic polyethers were synthesized in order to obtain new precursor architectures suitable for drug delivery systems. Polyglycidol‐6‐poly(ethylene oxide)‐b‐poly(D,L‐lactide) possess high hydroxyl functionality provided by the linear polyglycidol block. Thus very stable hydroxyl functionalized micelles in aqueous media were obtained. On the other hand poly(D,L‐lactide)‐b‐poly(ethylene oxide)‐b‐poly(propylene oxide)‐b‐poly(ethylene oxide)‐b‐poly(D,L‐lactide) form temperature sensitive aggregates. The copolymers obtained were analyzed by SEC and NMR, and their aqueous solution properties were followed by cloud point measurements and determination of critical micellization temperature. TEM was used for particles visualization.