Heat capacities of monoclinic Cr5Te8(m) and hexagonal Ni5Te8 (hex) have been measured from 325 to 930 K using an adiabatic scanning calorimeter. For monoclinic Cr5Te8 (m) the lambda-type heat capacity anomaly was observed at 815 K, presumably due to the order-disorder of chromium atoms and vacancies in chromium tellurides. The transition entropy change of the Cr5Te8 (m) sample obtained in this experiment compared reasonably well with that calculated on the basis of the order-disorder transition from vacancy-ordered Cr5Te8-type to vacancy-ordered Cr3Te4-type crystal structures. For the hexagonal Ni5Te8 (hex) sample two excess heat capacities were observed around 400 K and above 700 K. The excess heat capacity at low temperature may be connected to the order-disorder of nickel atoms and vacancies in this structure and that at high temperature may be related to the activation processes such as defect formation, electron excitation and electron-hole pair formation.