Determinations of heat capacities, C-p, and excess molar enthalpies, H-m(E), of the binary mixtures propylene carbonate + acetic or propionic acid were carried out at (285.15, 298.15 and 313.15)K using a Perkin-Elmer DSC differential scanning calorimeter and an LKB flow microcalorimeter. All experimental values are positive and increase with the increase of temperature. The data have been fitted to a simple cubic polynomial (for C-p) and the Redlich-Kister equation (for H-m(E)) to estimate the adjustable parameters and standard deviations of these systems. Results have been discussed in terms of molecular interactions and have been interpreted by an extended cell model.