Research on flexible assessment suggests that providing students with choice in assignments can increase motivation and deepen investment in learning. Although instructors are often advised to adopt flexible assessment, they are also warned about potential detriments such as perceived lack of rigour among colleagues, the stress that decision-making can bring to students, and increased workload for themselves. This paper draws upon student responses to a survey, a class discussion, and instructor observations to identify benefits and costs of flexible assessment in a fourth-year history course. Among the benefits are that students can pursue their interests more freely in both content and form, while the instructor can enjoy creative and original student work. The costs include anxiety among students who may be unsure how best to choose their assessments, and additional work for the instructor who must manage a multiplicity of assignments within the confines of an institutional grading system. The implementation of flexible assessment is recommended provided that the flexibility is compatible with the course's learning outcomes, the students' level of independence, and the instructor's capacity to take on an unpredictable amount of extra work. Suggestions are offered for how to implement flexible assessment without creating too much of a burden for either students or instructors.