We have investigated the interaction between (Bi,Pb)2Sr2Ca2Cu3O10+δ (Bi-2223) and small additions (0.05–0.3 wt %) of nitride powders (TaN, AlN, HfN, NbN, Si3N4, TiN, and ZrN) with a particle size from 0.02 to above 0.5 μm and the effect of these nitrides on the microstructure, phase composition, distribution, and morphology of the resulting second-phase inclusions. The concentration and particle size of the nitrides and sintering conditions are shown to influence the superconducting transition temperature T c, critical current density j c, irreversible remanent magnetization, bulk density, and mechanical properties of the Bi-2223/nitride composites. [ABSTRACT FROM AUTHOR]