This study analyzed global trends in the industrial use of anaerobic wastewater treatment systems. Information on over 750 anaerobic systems installed over the last two decades by three leading suppliers of anaerobic systems, namely ADI Systems Inc., Biothane Corporation, and Paques, showed exponential growth in the use of industrial anaerobic wastewater systems internationally up to the mid-1990s. After 1994, the number of annual installations declined, and has been relatively constant over the last three years. The North American market was shown to be relatively volatile, with no clear indication of future growth, while the European market was found to be relatively mature. In North America, most of the anaerobic wastewater treatment systems are serving breweries (26%), potato processing industries (11%), or pulp and paper industries (9%). An analysis of the market history of the commercial anaerobic models suggests the phasing out of traditional UASB and fermentor models, and the potential for growth of high-capacity and high-rate systems (>20 kg m⁻³ d⁻¹) such as the Biothane EGSB and the Paques Internal Circulation (IC) systems. Future efforts should focus on research into new designs for high-rate and high-capacity systems, and on the encouragement of economic incentives for industries implementing anaerobic wastewater treatment systems. A market study on other methods of wastewater treatment (e.g. aerobic treatment) is also recommended, to provide insight into current economic trends in the area of environmental biotechnology.