Heat capacities at constant pressure of 1,2-diaminoethane (1,2-DAEt) and 1,3-diaminopropane (1,3-DAPr) were measured within the temperature range from (293.15 to 353.15) K. The heat capacities of four other compounds, 1,4-diaminobutane (1,4-DABu), 1,6-diaminohexane (1,6-DAHx), 1,7-diaminoheptane (1,7-DAHp), and 1,9-diaminononane (1,9-DANo), were also measured between their melting point and 353.15 K. All measurements were performed by means of a DSC III (Setaram) differential scanning calorimeter. Assuming that molar heat capacity shows an additive character, a simple equation was proposed that allows one to describe C(p) values of liquid alpha,omega-alkanediamines as a function of temperature and the alkyl chain length with an accuracy below 0.5 %.