Despite the breadth of integrated writing assessment research, few studies have examined student perceptions of classroom-based integrated writing tasks or the instructional value of analytic rubrics. Adopting a case study methodology, this exploratory research investigated L2 learners' conceptualizations of integrated writing assessment and their use of an analytic rubric for self-assessment in an EAP writing course. Data sources included integrated writing samples that were evaluated by the students and their instructor, a writing self-efficacy questionnaire, individual retrospective interviews, and course materials such as syllabi, and task instructions. Qualitative analysis revealed themes related to three aspects of classroom-based integrated writing assessment: task requirements, task conditions, and instructor feedback. The themes were discussed in terms of students' test taking strategies and the use of available support systems in EAP contexts. In addition, findings indicated an overlap between students' self-assessment and instructor evaluation of their integrated essays, suggesting that students could use the evaluation criteria effectively. Implications for teaching and assessing integrated writing in EAP contexts are discussed.