Thermophysical study of the behaviour, as a function of temperature, of the 2-, 3- and 4-isomers of nitrobenzonitriles was carried out by differential scanning calorimetry, in the temperature intervals between 268 K and its respective melting points. The temperatures, enthalpies and entropies of the fusion processes were measured. Several phase transitions were observed for the 2- and 4-isomers and their temperatures, enthalpies and entropies are given. Heat capacities of the 2-, 3- and 4-isomers of nitrobenzonitriles were measured by differential scanning calorimetry between 268 K and their melting temperature and the results obtained were correlated as a function of temperature.