Presented here are experimental hydrate dissociation pressures for the (hydrogen sulphide + tetrahydropyran + water) and (methane + tetrahydropyran + water) systems over the temperature ranges of (293.5 to 305.0) K and (294.2 to 301.0) K, respectively. An isochoric pressure-search method was used to generate the experimental results. The hydrate dissociation data for the (methane + tetrahydropyran + water) system are compared with the literature data and the acceptable agreement (+/- 0.2 K at given pressures) confirms the reliability of the experimental method used in this work. To study the hydrate promotion effects of tetrahydropyran, the experimental results for both systems measured are compared with the corresponding experimental data in the absence of tetrahydropyran reported in the literature. It is shown that this promotion effect is remarkable. (C) 2012 Elsevier Ltd. All rights reserved.