Although biodegradable lubricants have been in use in the form of animal and vegetable fats and oils since ancient times, it is only since the 1970's oil companies have undertaken the task of developing high-performance biodegradable lubricants. This development of these oils has been in response to demands of the public and government regulation. The market for these materials is expected to grow faster than the rest of the lubricants market. An overview is given of the market for biodegradable lubricants, regulations influencing their use, biodegradability testing and formulation considerations including base oils and additives. Illustrative products including hydraulic oils made with various base stocks and a biodegradable motor oil are described. With the development of special base oils and additives of low toxicity, it is concluded that high-performance lubricants with acceptable environmental impact will be readily available.