Industrial fermentations need raw materials that fulfill the requirements of the organism (suitable carbon and nitrogen source, minerals and specific nutrients) and that are available in a high quantity and quality. This contribution gives a comprehensive overview, including the new trends and progress of recent years. The use of feedstock based on several raw materials such as sugar, starch, inulin and lignocellulose is discussed. Biomass-based raw materials are by far the most applied feedstocks for fermentation. However, there are also raw materials for fermentations derived from the petrochemical industry. These substrates are especially hydrocarbons, alcohols and carboxylic acids. Some applications are given in this chapter.