The effect of ultrafine hafnium nitride additions (0.05-0.2 wt %) on the microstructure, phase composition, density, and superconducting properties (T-c and j(c)) of (Bi,Pb)(2)Sr2Ca2Cu3O10+x ceramics is studied. The elemental composition of individual phases is determined, and the magnetic-field distribution in the ceramics is examined. The introduction of hafnium nitride increases the density of the ceramics and improves their microstructural stability at sintering temperatures between 840 and 850degreesC. The low hafnium solubility in the superconductor offers the possibility of attaining higher magnetizations and 77-K critical current densities.