The Chicago Tri-State metro-region is among the top five metro-regions in the US for specialisations in professional energy services, and the metro-region also exhibits specialisations in Air and Water Purification Technologies, Lighting, and Green Architecture and Construction Services. In the Chicago-area 21-county region, the Milwaukee metro-region has the strongest specialisation in the US in water efficient technologies. The growth of the green sector in the Chicago Tri-State metro-region has brought with it a significant number of green-sector jobs; the sector has grown by 20% since 2003. The metro-region could build on these strengths to improve economic and environmental outcomes in the long run. Energy efficiency retrofitting and green building design could be considered top priorities for job growth and distinguishing the metro-region’s green architectural expertise, but financing mechanisms for lowering the barriers to energy efficiency investments would need to be improved. Wind energy holds the promise of developing a sector that is beginning to call the Chicago Tri-State metro-region home, but needs clearer pricing signals and technical assistance to become more price-competitive.