Mn-doped ZnS nanoclusters were synthesized within microphase-separated films of diblock copolymers containing carboxylic acid units on one of the blocks. Zinc was selectively sequestered into the acid-containing domains by treating the films with diethylzinc or an aqueous zinc acetate solution. Manganese was loaded by subsequent treatment of the films with aqueous manganese acetate solutions. The manganese ions displaced a fraction of the zinc ions, and the extent of loading was controlled by varying the loading time, and the concentration of the manganese acetate solution. The extent of loading was tracked using ICP discharge emission spectroscopy. The doped nanoclusters were formed by subsequent treatment with H2S. The size of the doped ZnS nanoclusters could be varied by carrying out the H2S exposure in the presence of a coordinating base. Photoluminescence measurements revealed that the doped nanoclusters were photoluminescent, and showed the characteristic manganese emission. The universal doped cluster synthesis scheme used is quite general and can be easily modified to produce other doped nanocluster clusters, such as Tb-doped ZnS, or Mn-doped CdS.