Academic writing is used a lot in the academic field and general writing as a distinct genre discourse in the linguistic and socio-cultural fields. Good writers generally use well-formed sentences; they often establish connections between sentences. Writing an essay is still a critical problem for most EFL under- graduate students since they are still not able to establish connections between sentences. The purpose of this study is to investigate the usage of conjunc- tions as cohesive devices in expository essays produced by EFL fourth-year undergraduate students majoring in the English language at the Department of English language and literature, Hashemite University in Jordan. A corpus of 30 expository essays were collected by using a simple purposive sampling technique to answer the questions of the study based on the theory of cohesion analysis by refining the grammatical cohesive related aspect based on Halli- day and Hasan’s (1976) taxonomy of conjunction. The results show that addi- tive conjunction covers the largest proportion of (57.70%) followed by causal conjunction (6.44%), adversative conjunction (3.64%), and temporal conjunc- tion (3.64%). On the other hand, the analysis reveals that students use addi- tive conjunction (17.93%), causal conjunction (5.32%), adversative conjunc- tion (3.36%), and temporal conjunction (1.96%) inappropriately. This study contributes to the written discourse and pedagogy within the field of teaching English for academic writing. The study recommends that grammatical cohe- sive devices and their function should be explained to the students through explicit teaching, not as separated grammatical items but as discourse seman- tic resources of text creation.