Academic writing is quite distinctive and producing it requires high levels of language proficiency in general and sufficient knowledge in one's own disciplinary discourse in particular. This means that producing academic language is a hard task even for those students who write in their first language. Thus, the task would definitely be harder for those EFL students who write in a second/foreign language. This study explores the way Iraqi L1 and EFL postgraduates write from their sources and whether the medium of instruction they are writing in effects their source use practices. It is hypothesized that Iraqi MA students in most Arabic and English departments throughout the Iraqi Universities tend to misuse their sources, and thus produce texts that contain high levels of textual plagiarism. In order to verify the above hypothesis, extracts from 20 MA theses written by Iraqi L1 and EFL postgraduates were selected for analysis. The analysis was based on a comparative reading approach where MA student texts were compared to their retrievable sources. Findings show that all the L1 and EFL writing samples contained language repeated from sources without attribution, a thing that reflects how dependent both groups of students were on their sources.