Cohesive devices are explicit elements used to establish connections and transitions between sentences or paragraphs in order to create a unified text. This paper examines the grammatical and lexical cohesive devices used by Engineering and Technology and Humanities students to achieve coherence in their spontaneous texts, as well as the impact of students' academic discipline on their ability to develop coherent texts. The findings suggest that writers relied more on grammatical cohesive devices than lexical cohesive devices to accomplish coherence, and that the academic discipline influences students' writing abilities