Calcium- and lanthanum-modified lead titanate (PCLT) powders,vith size in the nanometer range were prepared by a sol-gel process. The PCLT gel was annealed at 850 degrees C to produce powder,vith an average particle diameter of 80 nm, A dense and fine-grained PCLT ceramic, with grain size of similar to 0.7 mu m, was prepared by sintering the sol-gel-derived powder at 1150 degrees C. The piezoelectric and pyroelectric properties of the PCLT ceramic varied linearly with the degree of poling in the ceramic. PCLT/vinylidene fluoride-trifluoroethylene (P(VDF-TrFE)) 0-3 nanocomposites with PCLT volume fractions of 0.1-0.5 were fabricated, using PCLT powders imbedded in a P(VDF-TrFE) matrix. The ceramic data were used to model the piezoelectric and pyroelectric properties of the PCLT/P(VDF-TrFE) composites, and good agreements were obtained.