Green-emitting iridium dendrimers with rigid hole-transporting carbazole dendrons are designed, synthesized, and investigated. With second-generation dendrons, the photoluminescence quantum yield of the dendrimers is up to 87 % in solution and 45 % in a film. High-quality films of the dendrimers are fabricated by spin-coating, producing highly efficient, non-doped electrophosphorescent organic light-emitting diodes (OLEDs). With a device structure of indium tin oxide/poly(3,4-ethylenedioxythiophene):poly(styrene sulfonic acid)/neat dendrimer/1,3,5-tris(2-N-phenylbenzimidazolyl)benzene/LiF/Al, a maximum external quantum efficiency (EQE) of 10.3 % and a maximum luminous efficiency of 34.7 cd A–1 are realized. By doping the dendrimers into a carbazole-based host, the maximum EQE can be further increased to 16.6 %. The integration of rigid hole-transporting dendrons and phosphorescent complexes provides a new route to design highly efficient solution-processable dendrimers for OLED applications.