Vegetable oil is the richest source of food energy, providing twice as much energy as the same quantity of carbohydrate or protein. In areas where peanuts (groundnuts) or other soft oil-seeds are cultivated, manual oil extraction using a screw press can be a viable enterprise for small businesses. The processes described in "The Manual Screw Press for Small-Scale Oil Extraction" are suitable for operation on a small-scale, which means they can be used by rural people to control the processing and marketing of cooking oil. This manual also explores how a small-scale oil processing production unit or enterprise can make the most of links with other businesses involved in utilizing the oilcake - such as making sweets or animal feeds, in order to create further business opportunities. This manual explains the essential steps to be undertaken before pressing the oil-seeds for maximum yields; such as crushing, adding water and heating, and how many hectares of groundnut will be needed to supply the oil press. The manual also details the planning necessary when considering setting up a small-scale oil processing enterprise. Advice is given on exploring the local market in order to establish what the demand for a particular product will be, how to draw up a business plan and obtain the necessary finance, how to organize production and market the oil and by-products.