In this paper, we report the crystal structure and thermodynamic parameters of zirconolite (CaZrTi₂O₇)which is a potential ceramic matrix for incorporation of nuclear high-level waste. The room temperature structural studies revealed a two layer monoclinic (C2/c) structure for the compound. Thermal expansion behavior of zirconolite was investigated by the high-temperature XRD. The average thermal expansion coefficient of zirconolite, measured in the temperature range 298–1273 K, is found to be: a-axis (Å ) = 12.410(2) + 1.06(8)* 10^-4 [T] + 3.1(5) *10^-8 [T]²/K, b-axis (Å ) = 7.252(1) + 6.2(4) * 10^-5 [T] + 4.9(2.5) * 10^-9 [T]²/K and c-axis (Å ) = 11.351(2) + 7.6(7) * 10^-5 [T] + 3.2(4) * 10^-8 [T]²/K. The standard molar enthalpy of formation of zirconolite (CaZrTi₂O₇, s) at 298.15 K determined employing high-temperature solution calorimetry is found to be - 3716.5 ± 3.7 kJ mol^-1. The isobaric heat capacity of the CaZrTi₂O₇(s) has been derived from the enthalpy increment (H_T–H_298.15) data. Based on the experimental data for the compound and the available thermodynamic data for the component oxides, thermodynamic functions like: Cp⁰_m,S⁰_m,H⁰_m,T,G⁰_m,T,(H⁰_T - H⁰_298.15 ),- (G⁰_T - H⁰_298.15 /_T) , ΔfH⁰_m,298.15 and ΔfG⁰_m,T for zirconolite (CaZrTi₂O₇, s) have been generated.