The enthalpy increment measurements were performed using drop calorimetry on two lanthanide zirconates Ln(2)Zr(2)O(7), Ln = La, Nd, with pyrochlore structure. The temperature dependence of heat capacity in the range (298 to 1550) K was derived by simultaneous linear regression of the measured enthalpies combined with the heat capacity data around ambient temperature. The obtained heat capacity C(p)degrees(T) is compared to the limit of constant volume lattice C-v calculated from the analysis of low temperature specific heat data using a combined Debye-Einstein harmonic approximation model. (c) 2005 Elsevier Ltd. All rights reserved.