This is a complete catalogue of the known Norwegian freshwater fauna (protozoa excepted). A total of 63 chapters with tables have been written by 38 Norwegian specialists, representing different zoological research institutions. In addition a number of persons have contributed species records, and comments on the manuscript. The work of the editors has been supported economically by the Directorate for Nature Management. The main part of the catalogue consists of chapters dealing with the various groups of animals, and tables of species distributions. The chapters are divided into sections, including biology/ecology, level of knowledge, conservation status, and literature. Disc included.