Conservation of animal genetic resources (AGR) in Scandinavia was started in the 1970s and organized in the 1980s. The work is coordinated by a working party financed by the Nordic Council of Ministers. Each country conserves its own AGR, but many tasks can be done jointly. Of these tasks, the development and maintenance of a Nordic data bank for AGR is an important part. Each country has mapped out its situation and prepared plans for conserving endangered native breeds and genetic variation in some major breeds for unpredictable future needs. Live animals from several breeds have been conserved in agricultural schools, prison farms and private herds, but these have been supplemented by stores of frozen semen and embryos. Developments in conservation methods are followed up and problems of conservation pointed out. Many of these are caused by the fact that animals grow, age, die and have to be mated regularly with unrelated animals, and that records have to be made of identities, mates, dates and traits. Many precautionary measures are necessary. Many-sided frozen semen and embryo stores are important besides live animal herds or flocks. There are problems in getting each female inseminated with an appropriate male, and in getting people working on different motives to collaborate.