Potential CO 2 reservoirs in Belgium are poorly explored. Consequently, the estimated storage capacities are theoretical capacities. The total theoretical storage capacity for Belgium is conservatively estimated at about 1Gt, additional exploration and research are needed to make better capacity assessments. An onset towards prioritising such actions is given here. Deep saline aquifers and coal sequences have created the geological storage options for CO 2 in Belgium. The main criteria for reservoir selection and evaluation are reservoir properties, sealing, depth and the occurrence of trapping structures. Aquifer storage opportunities are the Houthem and Maastricht Formations, the Buntsandstein Formation, the Neeroeteren Formation, the Carboniferous Limestone Group (Dinantian) and the Devonian, the latter two in both the north and the south of the country. Of these, the Buntsandstein and the Dinantian reservoirs appear the most promising. Unmined coal sequences have a relatively large capacity, but the low permeability will pose technical difficulties. Storage in abandoned coal mines is likely feasible but pressure and sealing issues will have to be solved.