The use of ferroaluminum is increasing in steel mills and foundries in the United States and overseas. The paper reviews aluminum deoxidation briefly, with emphasis on efficiency and oxide inclusion removal, then discusses the properties of ferroaluminum which give it superiority over metallic aluminum as a deoxidizer. Current steel mill and foundry experience and operating practice are reviewed, with special attention to the use of ferroaluminum as a furnace blocking addition, a primary and final deoxidizer, and as a means for increasing the accuracy and precision of oxygen probe measurements.