This review discusses the recent experimental heat capacity measurements which have been very useful in physicochemical investigations. Areas reviewed include critical point phenomena in systems such as fluids, magnetic systems, liquid crystals, co-operative Jahn-Teller transitions, etc. The uses ofCpmeasurements in the study of discrete energy levels in solids, in glasses at very low temperatures, in thin films and at high pressures are discussed. Calorimetric investigations in A-15 and other superconducting materials and applications ofCpmeasurements for evaluation of thermodynamic parameters in several new classes of materials are then briefly described. Finally, examples of applications of calorimetry in areas of biophysics, biological sciences and clinical medicine are cited. Two hundred and seventy references are cited and 25 figures are used for illustration.