The isobaric molar heat capacities as a function of temperature and pressure are, for the first time, reported for a set of imidazolium-based ionic liquids. The selected compounds belong to the 1-alkyl-3-methylimidazolium series, concretely, [Emim][BF4], [Bmim][BF4], [Hmim][BF4], and [Omim][BF4]. Isobaric heat capacity were determined in the temperature and pressure intervals of (283.15 to 323.15) K and (0.1 to 60) MPa using a micro DSCII calorimeter recently adapted to work at high pressure. The data at atmospheric pressure were compared with literature data; as a rule, good results were obtained for all liquids. Isobaric molar heat capacities for the studied ionic liquids show quite a different behavior than that obtained for usual organic solvents, which could be understood as these compounds behave like highly compressed molecular fluids. This is consistent with the behavior of other previously reported thermodynamic properties.