Understanding students' reactions to their feedback to coursework is crucial in being able to deliver feedback which motivates them and helps them to do better. This study focused on undergraduate bioscience students on a variety of degree programmes, at three UK universities, across all years. A questionnaire was completed by students when first reading their feedback, thereby accessing their initial reactions to the comments they received. Focus groups assisted in the analysis of these initial reactions and also enabled discussion on how the students felt about their feedback. Our findings suggest that, although many students value feedback irrespective of their emotional response to it, others are clearly motivated or de-motivated by specific factors within the feedback that they receive. We suggest that this initial emotional reaction is fundamental to the student's subsequent engagement with feedback, and that feedback that immediately de-motivates a student is likely to be of very limited value to the ongoing learning process. Recommendations to improve feedback include the need to offer positive, constructive comments, meaningful annotations and comments which justify the given mark. (Contains 7 tables and 7 figures.)