Rapid consumption of energy resources, increasing energy needs, the competitive conditions in the industry and environmental concerns, all of those call for efficient use of energy resources. In this context, energy efficiency studies were carried out in a rolling mill of a reheating furnace of an integrated industrial enterprise. In studies, some important efficiency measurements were conducted, mass and energy balances were established by using the results of these measurements and the operating data of the plant along with energy saving opportunities, with the specified amounts and repayment periods were determined. Energy conservation studies that can be realized in the reheating furnace were considered including operation of the reheating furnace with the pertinent excess air coefficient, compensation of the air leakage losses in the recuperator and establishment of the economizer in the furnace. As a result of these investigations some saving opportunities were determined and a new recuperator, economizer and gas analyzer were installed in the reheating furnace leading in total of 2,913,924 kcal/h of energy savings. After the implementation of energy saving measures, reheating furnace efficiency was increased from 61.83% to 69.43%.