The distribution of in-situ stresses in the hot rock masses related to geothermal resources can be complicated. The uncertainties on these stress distributions can pose significant challenges to engineering design across a variety of activities related to wellbore drilling, well completion, reservoir stimulation, and reservoir management. Over the years, many methods have been utilized to determine in-situ stresses, but most experience is in low temperature environments relevant to the oil/gas, mining, and civil applications for which the methods were originally developed.  The experience in high temperature environments at great depth and in crystalline rocks is considerably less. Stress estimation for Enhanced Geothermal Systems (EGS) wells can therefore pose unique challenges that motivate innovations in methods of measurement, analysis, and interpretation in the area of in-situ stress estimation. This session is aimed at bringing together researchers and practitioners in the area of in-situ stress estimation for EGS reservoirs in order to clarify the most significant challenges and share the latest innovations. The session will seek contributions related both to well-established stress estimation techniques that are being brought from other application areas into the EGS environment, as well as emerging methods that are suited to EGS stress estimation. The anticipated outcome will be a session that gives an overview of the state of the art, most relevant challenges, and the technological growth being realized in EGS stress estimation around the world.