Within the context of rising overall awareness of the climate change problem, CO2 capture and storage has risen rapidly on the policy agenda. Some Stakeholders have suggested that technology, cost and legal questions around CCS are all but solved. However, while policymakers embark on the agreement of national, European and international legislation on CCS, a number of challenges arise. This paper reviews the progress of CCS towards a legally embedded mitigation option, and identifies three major conditions for the acceptability of CCS deployment: social acceptance by stakeholders and the lay public, robustness of economic and cost data, and legal and regulatory consistency. Technical maturity and reliability are important crosscutting issues that need to be fully addressed before any of the other areas can be solved. It is concluded that, although legal and regulatory issues are close to being resolved, the role that CCS may play in the global energy system has likely been overestimated in system models, which is partly due to transparency and information problems. In addition, resistance from environmental organisations may have to be reckoned with and social acceptance of CCS remains one of its most prominent unknowns.