Owing to the green revolution, environmental problems have now become some of the most important issues worldwide. Environmental knowledge management, which combines the strengths of environmental management and knowledge management, will become a popular tool for businesses in the near future. In this paper, through interviews of staff at different levels and in different departments of the business, i. e. managers and engineers and using the environmental knowledge circulation process, the authors evaluate the success of environmental knowledge management when applied to China Steel Corporation in Taiwan. From the case study, the authors found that China Steel Corporation has applied the environmental knowledge circulation process for over thirty years. The company continually improves its environmental and financial performance through environmental knowledge creation, environmental knowledge accumulation, environmental knowledge sharing, environmental knowledge utilization and environmental knowledge internalization. Water pollution and air emissions have reduced year on year and total energy consumption has reduced by 20 % from 1979 to 2006. On the other hand, China Steel Corporation also makes a profit and reduces cost through energy sold, by-products and recycling. Continuous improvement in environmental knowledge management has rendered China Steel Corporation in the most profitable steel company in Taiwan and the world’s twenty fifth largest steel producing company in 2006.