The one-pot synthesis of core/shell quantum dots (QDs) represents an attractive alternative to conventional synthesis techniques, where the core CdSe QDs are first purified and then an epitaxial shell of the desired thickness is obtained by the slow addition of shell precursors to a solution of the purified QDs at high temperature. We have developed a one-pot synthesis procedure involving the successive injection of deliberately selected core- and shell-forming reagents at appropriate temperatures. Sub-kilogram quantities of highly luminescent and monodisperse core/shell QDs with desirable optical properties (full width at half maximum of photoluminescence (PL) band is ca. 30 nm) have been produced by the sequential growth of the core and shell in a controlled manner. This one-pot method has also been extended to form water-soluble core/double-shell CdSe/ZnSe/ZnS QDs exhibiting high PL efficiency and stability.