The revised version of FiSAT (FiSAT II) is a programme package consisting of methodologies for use with computers, enabling users to formulate some management options for fisheries, especially in data-sparse, tropical contexts. The FiSAT II was developed for computers running on Microsoft Windows (R) operating system. The new version utilises the standard Windows graphic user interface. FiSAT II was developed mainly for the analysis of length-frequency data, but also enables related analyses, of size-at-age, catch-at-age, selection and other data typically collected for tropical fish stock assessment. This volume is complemented by FiSAT - FAO-ICLARM stock assessment tools. Vol. 2: Reference manual, ISBN 92-5-104047-8.