The heat capacity Cp of powdered specimens of Mn(CH3COO)2.4H2O has been measured between 0.4 and 20°K in two vacuum calorimeters, one of which was cooled with liquid He3. A sharp λ-like anomaly occurs at 3.18°K, the magnetic ordering temperature. The behavior of this peak upon application of a magnetic field supports the conclusion that the ordered phase is ferrimagnetic. Near 0.7°K, Cp exhibits a rounded anomalous maximum of the Schottky type. This probably reflects the inequivalence of Mn++ ions within the unit cell. It is suggested that one group of Mn++ ions may interact only weakly with another group which are comparatively strongly coupled to one another.