Feedback is an important part of the learning process. However, the relative effectiveness of feedback in any given situation is poorly understood. Student retention of different forms of feedback is also largely unexplored. This case study examined the relative student perception and retention of both verbal and written feedback, using 68 level 4 bioscience students. The majority of these students preferred written feedback, although a third of the students stated a preference for verbal feedback. There was no significant difference in the percentage of verbal and written feedback retained by students. The results raise the possibility that the effectiveness of feedback can be empirically measured, allowing a more evidence based approach to the provision of different forms of feedback delivery. (Contains 4 figures.)