Many types of drugs and agents used for cancer diagnosis and therapy often have low bioavailability and insufficient efficacy, as well as causing various side effects due to their nonspecific delivery. Nanocarriers with purposely-designed compositions and structures have shown varying degrees of abilities to deliver these compounds towards cancers in passive or active manners. Despite the availability of a variety of materials for the construction of nanocarriers, natural polymers with good biocompatibility and biodegradability are preferable for such usage because of their high in vivo safety as well as easy removal of degradation products. Among the natural polymers intended for building nanocarriers, hydroxyethyl starch and its derivatives have gained tremendous attention in the field of drug delivery in the form of nanomedicines over the last decade. There is growing optimism that ever more hydroxyethyl starch-based nanomedicines will be a significant addition to the armoury currently used for cancer diagnosis and therapy.