This is an empirical investigation into the use of dictionaries by students of English and Science at Kuwait University with a particular focus on bilingual dictionaries of Arabic and English. In the introductory chapter we discuss the increasingly important role of vocabulary in EFL methodology and the relevant emphasis on improving existing dictionaries and teaching students how to make effective use of them. In chapter two we focus on bilingual dictionaries and review their status in EFL methodology. Then structural features of this type of dictionary are discussed with special reference to the problems of translation equivalents, sense discriminations, and intended dictionary function. Chapter three is a critical examination of two bilingual dictionaries in Kuwait. AL-MAWRID (English-Arabic) and DlcrIONARY OF MJDERN WRI'lTEN ARABIC (Arabic-English) are examined in terms of their users and uses, introductory matter, translation equivalents, sense discriminations, illustrative examples, collocations and idioms, grammatical information, and pronunciation. In the fourth chapter we review previous studies of dictionary users and uses and focus on their findings which bear relevance to our investigation. Chapter five is a description of the research method we follow in our investigation i.e. a questionnaire and two translation tests. In chapter six we present and analyse the findings on specific aspects of dictionary use addressed in the questionnaire. Chapter seven is an analysis of translation errors in relation to the type(s) of dictionary used in the Ll-L2 and L2-Ll translation tests. The final chapter summarises the research findings and presents same suggestions with regard to the improvement of existing bilingual dictionaries of English and Arabic and the training of dictionary users.