Excess molar enthalpies, H-m(E), have been determined for propylene carbonate + five linear ketones (2-propanone, 2-butanone, 2-hexanone, 2-octanone, or 2-undecanone) and + three cyclic ketones (cyclohexanone, 2-methylcyclohexanone, or 2,6-dimethylcyclohexanone) at 298.15 K and atmospheric pressure by means of an LKB flow microcalorimeter. Results have been correlated using the Redlich-Kister equation, and the adjustable parameters have been evaluated by the least-squares analysis. H-m(E) values are found to be positive for all mixtures with the exception of propylene carbonate + 2-propanone, which shows a sign inversion of H-m(E).