After a brief review of the search for hydrocarbons that has been carried out since 1953 by the Belgian Geological Department (Service Geologique de Belgique), the authors assess the chances of discovering underground hydrocarbon deposits in Belgium, in light of the exploratory drilling done at Focant and St. -Ghislain. It is recommended that the prospecting be continued in the Namur Basin, in the area where this basin is hidden by the Dinant Basin.