AThe heat capacity of natural lead molybdate (wulfenite, PbMoO4) has been measured by the method of vacuum adiabatic calorimetry over the temperature range of (55 to 320) K, and its thermodynamic functions have been calculated. The obtained standard values are as follows: C-p degrees (298.15) = (119.41 +/- 0.13) J.mol(-1).K-1, S degrees(298.15) = (168.33 2.06) J.mol(-1).K-1, Delta H degrees = (23 095 +/- 50) J.mol(-1). For extrapolation of heat capacity values to absolute zero, the equation C(T) = (AT(-1/alpha beta) + 1)(-1/alpha) has been used, where parameter a. is the power at which the heat capacity verges toward the Dulong and Petit limiting value, and parameter beta reflects structural anisotropy of the compound and can possess values from 1 to 3. The values of parameters found by means of linearization were alpha = 0.61 and beta = 1.9. An error for the extrapolation data to absolute zero has been estimated based on the results of heat capacity measurements of the isostructural compound calcium tungstate, CaWO4. The values of the wullenite heat capacity Over the range of (0 to 55) K have also been calculated by the semiempirical method MNDO with the help of a program package on quantum-chemical computation (MOPAC) and according to the method of interatomic potentials within the bounds of dynamics of crystal lattice theory using the computer program LADY.