The aim of this paper is to determine the size of regional enlargement and strengthening in Sweden over a period of eight years and the relationship with economic growth by analyzing changes in commuting patterns in that period using geographical information system (GIS) techniques. For this analysis, commuting regions have been delimited using the classic concept of commuting field for one-way flows from homes to employment centres functioning as central places. The delimitation procedure is supported by a geo-processing model that automates the process of building such fields. The analysis results show that substantial regional enlargement and strengthening occurred around major employment centres between 2000 and 2008. More than 40% of municipalities could enlarge their commuting field, while for more than 80% of municipalities in these fields their orientation to the core of such a field increased. A significant strong, positive correlation exists between economic growth and regional strengthening, expressed by an increased orientation to the core municipality of a commuting field of commuters living in surrounding municipalities and decreased internal commuting in the core municipality. Municipalities with enlarged commuting fields have on average more employment growth than municipalities whose fields have not changed. There is no indication that regional enlargement of an employment centre is influenced by growing numbers of employed residents in surrounding municipalities.