In the context of the urgency of climate change and the need to drastically reduce greenhouse gases in the atmosphere, it is essential to capture and store unavoidable CO2 emissions, alongside other vital emission reduction measures. Indeed, some CCS is essential to achieve the 2050 carbon neutrality targets that industrialised countries have set themselves. The Caprock Integrity & Gas Storage Symposium (CIGSS) aims at providing and establishing a platform for the exchange and discussion of scientific, technological, industrial, and regulatory advances related to the integrity of caprocks in the context of geological storage of CO2 and gas storage in general.