A study was conducted on the effects of microstructure, atmosphere, and several dopants on the electrical conductivity of bismuth titanate (Bi4Ti3O12, BIT), Increased grain size increased the conductivity in undoped BIT as did acceptor dopants that substituted for either Bi (Ca and Sr) or Ti (Fe), A donor dopant (Nb) decreased the conductivity in BIT by as much as 3 orders of magnitude, The increased resistivity of Nb-doped BIT improved the polarization in an electric field, A piezoelectric coefficient, d(33), of 20.0 pC/N was achieved with a Nb-doped BIT composition corresponding to Bi4Ti2.86Nb0.14O12.