Measurements leading to the calculation of the standard thermodynamic properties for gaseous 2,3-dihydrobenzo[b]thiophene (Chemical Abstracts registry number [4565-32-6]) are reported. Experimental methods include combustion calorimetry, adiabatic heat-capacity calorimetry, vibrating-tube densitometry, comparative ebulliometry, inclined-piston gauge manometry, and differential-scanning calorimetry (d.s.c.). Critical properties are estimated for 2,3-dihydobenzo[b]thiophene. Standard molar entropies, standard molar enthalpies, and standard molar Gibbs free energies of formation are derived at selected temperatures between T = 298.15 K and T = 680 K. Crown Copyright (C) 2003 Published by Elsevier Science Ltd. All rights reserved.