This book is an up to date compendium of all information available up to 1997 in respect of the freshwater fish fauna of this region . The classification adopted is generally after Nelson's Fishes of the World (1994), Howes (1991) with inputs from Eschmeyer's Genera of Fishes (1990). For Cyprinine genera the order of an arrangement proposed by Rainborth (1991) has been adhered to. In respect of nemacheilines the arrangement proposed by Banarescu and Nalbant (1995), Kottelat (1990) have been followed. As indicated in the title the Indian region as conceived here includes India, Pakistan, Bangladesh, Mayanmar, Nepal and Sri Lanka within their political boundaries. Afghanistan and other border areas excluded. All primary freshwater fishes are definitely listed and many secondary and peripheral species that visit freshwater are also included. A uniform pattern of citation is adopted. Brief salient features of all the taxa up to orders are given. Descriptive details in respect of families and genera are provided more elaborately. Synonymies include the latest valid name, first reference, type-designations and more important pertinent references to that taxa. All citations have been checked, and cross-checked with the aid of Eschmeyer's work. Species are not described but listed alphabetically with their known range of distribution, but genera are described and arranged according to their known phylogenetic and intergeneric affinities. Keys are provided and simple drawings illustrating characters where needed are given. Synonyms, notes on species, genera, nomenclatural clarifications are given as foot-notes against relevant species marked with an asterisk, but in the foot-note the same serial number alone is cited and not the full species name. Figures depicting a representative of most genera can be seen; for many genera the more common species are illustrated as plate figures. A total of 272 genera with 852 species falling under 71 families and 16 orders are dealt with in this book. A glossary of 218 technical terms with adequate illustrations and a bibliography of 649 references are given. 241 figures and 18 plates are in the book. An addenda made up to date carries brief information of one new genus, 11 new species and one new subspecies.