This paper introduces the Quick-E-Scan methodology that has been developed to achieve the operational energy efficiency of small & medium enterprises (SMEs), characterized by being scarcely disposed to long energy audits and by a limited budget for energy management programs. On one side, through dividing the firm into functional units - either service (lighting, HVAC, etc.) or production units - the main consuming areas are identified and a criticality index is defined; conversely, an enhancement index highlights the gap of each unit towards the best available techniques (BATs) in energy management programs. Finally, a priority index, created with the junction of the two indexes, points out the most profitable areas in which energy saving measures should be implemented. The methodology, particularly quick and simple, has been successfully tested in 38 SMEs in Northern Italy. (C) 2010 Elsevier Ltd. All rights reserved.