The still unreached goal of nanomedicine is to deliver drugs which are only released in the diseased tissue in a controlled fashion. For this, tailorable, reproducible, and highly controlled drug delivery systems are required. Whereas nature uses discrete building blocks, the current status quo in drug delivery is the use of ill-defined polydisperse macromolecules. Synthetic efforts in material science yielded discrete macromolecules which have astonishingly different properties than their polydisperse counterparts. Here the self-assembly of discrete block-co-oligomers in water is compared to their polydisperse counterparts. Gaining structural insight into these systems will help in establishing the effect of monodispersity on size, architecture, core-crystallinity and packing, all important parameters to control stability and the uniformity of drug release.