The performance of ferroelectric materials as converters of thermal into electrical energy has been analyzed in terms of their fundamental dielectric and thermal properties. The time dependent operation of a single stage pyro-ferroelectric converter performing a spontaneous cyclic process has been evaluated, leading to expressions for the specific power, current and voltage outputs in terms of the relevant static and transport parameters. It is concluded that ideal efficiencies of the order of 10-15% could be attained if proper materials with relatively large performance factor are developed to be used in multistage converters operating under large ΔT's.