Caledonian College of Engineering, Oman, has been encouraging its students to use monolingual dictionaries rather than bilingual or bilingualized ones in classroom and during the exams. This policy with has been received with mixed feelings and attitudes. Therefore, this study strives to explore teachers' and students' attitudes about the use of the dictionary and its training. Questionnaires were administered to 20 teachers and 100 students to collect their perceptions about the use of monolingual dictionaries at the expense of bilingual dictionaries. The results revealed that the vast majority of the teachers prefer their students to use monolingual dictionaries because they will help them acquire foreign language more effectively and that the bilingual dictionaries are likely to encourage translation, whereas most of the students would prefer to use bilingual and bilingualized dictionaries because they feel they are practical and easy to use. The study puts forward some recommendations and strategies for the effective use of the dictionary, the basis of a good learner dictionary, challenges of using monolingual dictionaries and possible training strategies for dictionary use.