Low-temperature heat capacity of tetrameric cobalt(II) acetylacetonate (tetrakis[bis(2,4-pentanedionato)cobalt(II)], [Co(C 5 H 7 O 2 ) 2 ] 4 ) was measured by an adiabatic method in a temperature range from 13.49 to 310.31 K. No phase transition-associated anomalies in the functional behavior of the heat capacity were detected in the entire tested temperature range. The obtained data were used to calculate the Debye characteristic temperature and integral thermodynamic functions (entropy, enthalpy, and reduced Gibbs energy) in a temperature range of 0 to 310 K. The absolute entropy values were used to calculate the formation entropy of [Co(C 5 H 7 O 2 ) 2 ] 4 at T = 298.15 K. A correlation was found between the unit cell volume, normalized to the number of molecules in this cell, and the heat capacity at T = 298.15 K.