The FAO Inland Water Resources and Aquaculture Service (FIRI) has been active in promoting the use of geographic information systems (GIS) and remote sensing since 1985. However, a manual to use along with GIS software for the fisheries biologists in the field, explaining the use of GIS in inland fisheries management in a way that is understandable to non-GIS users, had not been produced by FIRI until now. This manual has been written to overcome this knowledge-gap, as a do-it-yourself-manual giving a short introduction to GIS software and its applications in fishery science. The overall objective is to encourage fishery managers to use GIS to foster the sustainable use of natural resources. It is aimed at fisheries biologists, aquatic resource managers and decision-makers in developing countries who have no knowledge about GIS, and will be useful for a broad range of fishery applications. Although the manual by no means covers all the possibilities of GIS, it touches upon some of the most important features for fisheries management and planning.