An expression of the thermodynamic potential is examined in terms of the primary and secondary pyroelectric coefficients of a poled ferroelectric ceramic. Anisotropic expansion and zero electric field conditions are assumed. The pyroelectric coefficient is applied to the composition, Pb(Zr0.95Ti0.05)O3(PZT 95/5) with 1 wt. % of Nb2O5, for which a complete set of elastic, piezoelectric, thermoelastic, and pyroelectric coefficients were determined. A value of −26.8×10−9C/cm2‐°C was found for the total pyroelectric coefficient of which +3.77×10−9was contributed towards the piezoelectric or secondary effect; therefore, −30.6×10−9C/cm2‐°C is reported for the primary pyroelectric coefficient for this material over the temperature range 25°–50°C.