The concept of organic farming is based on a holistic viewpoint. Nature is more than just the separate individual elements into which it can be split. Principles and ideas of farming are found in the science of ecology, the interrelationship of living organisms and their environments. The concept includes economic and social aspects of agricultural production, locally as well as globally. Organic farming aims to support and strengthen biological processes, without replacing them using technical remedies, and to adopt a preventive approach to the control of weeds, pests and diseases. Consequently, the use of chemical inputs, such as synthetic fertilizers and pesticides, is not allowed. Organic farming is based on enhancement of soil structure and fertility as well as a balanced choice of crops, for instance by the implementation of diversified crop rotation systems. The number of animals and the land area is harmonized so that farm units can cover their need for feed and nutrients are kept within the system. Key characteristics of organic farming include the use of organic materials for maintaining organic matter and nutrients in the soil; nitrogen-fixing plants; appropriate soil management techniques, including mulching and fallow periods; resistant varieties; compatible cropping systems (e.g. inter-cropping) and agroforestry; practices giving due consideration to animal welfare; biological control of pests, and manual, mechanical and thermal weeding. In order to ensure that products claimed to be organic are actually produced according to organic farming principles, they must be certified as such. By certification a third party gives written assurance that products labelled organic are produced according to the standards applicable in that market, making certification a necessary condition for international trade in organic products. This paper is meant as an introduction to the factors influencing world trade in organic food and beverages. It does not seek to provide an overview of the organic citrus business, though citrus products will be referred to whenever information is available.