Information has proven to be an important barrier in industrial energy efficiency improvement. Voluntary government programs aim to assist industry to improve energy efficiency by supplying information on opportunities. ENERGY STAR® supports the development of strong strategic corporate energy management programs, by providing energy management information tools and strategies. This paper summarizes ENERGY STAR research conducted to develop an Energy Guide for the Petroleum Refining industry. Petroleum refining in the United States is the largest in the world, providing inputs to virtually every economic sector, including the transport sector and the chemical industry. Refineries spend typically 50% of the cash operating costs (e.g. excluding capital costs and depreciation) on energy, making energy a major cost factor and also an important opportunity for cost reduction. The petroleum refining industry consumes about 3.1 Quads of primary energy, making it the single largest industrial energy user in the United States. Typically, refineries can economically improve energy efficiency by 20%. The findings suggest that given available resources and technology, there are substantial opportunities to reduce energy consumption cost-effectively in the petroleum refining industry while maintaining the quality of the products manufactured.