A survey of the current practice of process control and economic performance was carried out in 2007 (850 relevant professionals and 2 600 members of the South African Institute of Mining and Technology and professionals who had published papers on control of grinding mill circuits were contacted directly). The results already published in 2008 are elaborated in the present paper. The aims of this survey are to determine how milling circuits are currently controlled and to find out how key process variables are linked to economic benefits. The survey involves background information on the circuits, the choice of controlled and manipulated variables, the economic impact of the controlled variables, the control technology adopted and the assessment of control performance. Sixtyeight responses were received. The survey results were contrasted to the milling control literature and important conclusions were drawn.