Dendrons up to generation 3 were quickly synthesized using two sequential steps of diazo transfer and click chemistry reactions. The building blocks for dendron synthesis were made by incorporating monodisperse oligoethylene glycol (OEG) chains of exact length onto diethyelenetriaminepentaacetic acid (DTPA)-derived moieties to obtain first-generation dendrons. Afterward, the amine groups of the first-generation core dendron were converted to azides by means of the diazo transfer reaction. The second- and third-generation dendrons were constructed using the copper-catalyzed azide-alkyne cycloaddition (CuAAC). Hemocompatibility studies including hemolysis, red blood cell morphology, cell count and size distribution, hemostasis, and complement system activation were performed to evaluate their safety in blood.