This work reports new vapour pressure data of epsilon-caprolactone, delta-hexalactone, and gamma-caprolactone. Vapour pressure measurements were carried out over the temperature range of (283 to 343) K using the static method with a differential pressure transducer. Degassing was performed inside the equilibrium cell by freezing and thawing the samples under moderate vacuum (about 50 kPa). For epsilon-caprolactone and delta-hexalactone vapour pressure values varied in the range of (0.045 to 0.769) kPa and (0.005 to 0.354) kPa, respectively, while for gamma-caprolactone a maximum value of 1.367 kPa was found. Experimental vapour pressure data were correlated by the Antoine equation with a good agreement between experiment and model. (c) 2007 Elsevier Ltd. All rights reserved.