Thus, it is the first bhingual Dictionary giving the latest and most up-to-date Hindi equivalents for scientific and technical terms. We have followed the principles and methods of lexicography as evolved by the Central Hindi Directorate in their lexical work: Hindi equivalents for the scientific and technical terms have been taken from the terminological glossaries prepared by the Directorate and published in 1974. Also Chambers Twentieth Century Dictionary has a most comprehensive and broad-based vocabulary, incorporating latest words in its edition of 1977 published by the Allied Publishers, which has been the basis for this bilingual Dictionary. Most of the compilers of English-Hindi dictionaries, because of the problem of the copyright, have to select English words for entries and in the selection they fail to adept any uniform pattern. It is for the first time that an English-Hindi Dictionary has been prepared based on any one standard English-English dictionary. It is in this Context that ‘Chambers English-Hindi Dictionary’ acquires a special significance. Despite this fast multiplying lexicographical literature, no sound principles and methods have been discernible in these efforts for the preparation of English Hindi bilingual dictionaries The task of the lexicographer in the preparation of bilingual dictionary has become difficult and complex, because of the unprecedented growth of Hindi vocabulary, especially in regard to science, technology and humanities The mixed character of Hindi vocabulary and the lack of standardised usage makes the task of the lexicographer all the more difficult in coordinating the lexical units of the source language (English) with the target language (Hindi). During the last thirty years a number of English-Hindi dictionaries have been brought out to meet the growing demand.