Coherence is a key attribute of successful undergraduate writing. When a student produces a text which is difficult for a reader to follow, the success of their writing is compromised regardless of the merit of their ideas. While English as a Second Language (ESL) writing instruction tends to focus on coherence problems related to grammatical errors or cohesive devices, ESL teachers lack a systematic way to address discourse-level coherence in the classroom. Previous studies have shown that Systemic Functional Linguistics, and in particular the theme-rheme analytical framework, can be used to identify cohesion and coherence difficulties in student writing and should be incorporated into writing curricula. However, very few studies have analyzed more than one or two student essays in their research and only offer theoretical advice on how to incorporate the theme-rheme analytical framework into the classroom. This thesis analyzed the theme and rheme patterns in eight undergraduate ESL essays, four of which were evaluated as being high in coherence and four of which scored low, in order to explore whether the theme-rheme choices can characterize coherence in writing. The study found that high scoring coherent essays employ dense and complex nominal groups in ideational themes, a wide variety of textual themes, and different forms of thematic progression to establish connections between different parts of the text and comment on abstract ideas relevant to the topic. In contrast, low scoring papers frequently overuse unmarked themes of simple nominal groups or pronouns and overuse theme reiteration in a way that makes the text difficult to follow and appear to lack development. Based on the results of the study, specific teaching materials were created to provide a model of how the theme-rheme analytical framework can be incorporated into an academic writing curriculum.