Gross Regional Domestic Product (GRDP) is a measure of production on a territory whatever the presence of the factors that generate it. To measure the income generated by the factors labour and capital that are present in an area, it is necessary to refer to the concept of Gross Regional Income (GRI). The Belgian statistical services do not offer any official measure of the GRI of the Belgian regions. This is why, after clarifying the concept of GRI and describing the principles of regional apportionment, the paper carries out an estimation of the Belgian GRI's during the period 1995-1999. Thus, for 1999 for example, the estimated shares of GRI of Brussels, Flanders and Wallonia are respectively equal to 13.7%, 59.7% and 26.6% when the shares of GRDP amount respectively to 19.1%, 57.2% and 23.7%. ; info:eu-repo/semantics/published