9. The cultivation of oyster mushrooms world-wide has increased more than 25-fold during the last thirty years. The worldwide production of oyster mushrooms was 35,000 tons in 1981 and around 875,000 tons in 1997. In 1997 the Pleurotus spp. accounted for 14.2% of the world production of mushrooms (Chang and Miles, 2004). However, Chang and Miles (2004) also refer to a publication in Chinese, The Market of Edible Fungi, which states that Pleurotus spp. are the second most important cultivated mushroom in China (26% of the market), and that in 2000 the production was more than 1,722,000 tons. No data on world production from the last fifteen years have been found.