Of the major components found in lean sour natural gas (CH4, H2S, CO2, H2O), hydrogen sulfide (H2S) readily forms the one of the highest temperature hydrates in the presence of water (structure I). Thus, when heating wellheads, flowlines, processing and injection facilities, the H2S hydrate formation conditions dictate the design for flow assurance purposes. Due to the high toxicity of H2S, there is a paucity of hydrate formation/dissociation condition data in the literature, especially in the liquid H2S region. In fact, there are only four previous experimental decomposition measurements reported in the literature for liquid H2S. In this work, we report the dissociation of pure H2S hydrate in the presence of water for p = 0.360 to 16.343 MPa and T = 285.23 to 304.04 K. These measurements were carried out in a 25 cm(3) stirred autoclave cell, where both the Lw-H-H2S(g) and Lw-H-H2S(l) phase boundaries were autonomously measured by using the phase boundary dissociation method. These new measurements augment our previously reported data, which were below the vapor pressure of H2S. The results obtained were used to fit a semiempirical Clausius-Clapeyron equation for the rapid calculation of H2S hydrate formation conditions. Also, the results were thermodynamically modeled using the reference quality reduced Helmholtz energy equations of state and the van der Waals and Platteeuw model for fluid and hydrate phases, respectively. Finally, the results obtained from the model were compared to available literature where the uncertainty in temperature was found to be within an average 0.2 K.