It has recently been widely recognized that code-switching is prevalent in Jordanians' daily conversation in various situations such as home, cafés, universities, restaurants and clubs. Abalhassan and Alshalawi (2000: 183) made a very related observation on code switching behavior among Arab speakers of English that “without exception, all respondents switched into English to some degree”. This could be referred to the increase number of technological advances and people travelling across countries for pleasure or for pursuing further education. In light of this observation, the crucial role of language in people's life, ambivalent attitudes towards code-switching (Akbar, 2007), the dearth of research in this area, such a present study is required to explore Jordanian university students’ and instructors’ perceptions of code-switching in their daily classroom conversation and its expected impact on their language proficiency. In particular, it investigates the factors leading them to code mix and their underlying attitudes towards its expected future impact on their language proficiency. To the best knowledge of the present researcher, this study is the first of its kind in Jordan. Data was collected via semi-structured interviews and a questionnaire from 70 university students and 30 instructors from both Philadelphia University and the Hashemite University. Data revealed that code mixing between English and Arabic is a common phenomenon in lectures they have attended in their academic institutions. The participants also show that they find code mixing fascinating and believe that though code switching might have a positive impact on their learning as it helps them better understand the topic. The instructors revealed that code mixing fulfill a set of functions that serve the educational process.