Problem based learning is a successful teaching and learning strategy used to engage students in deep rather than surface learning and where the learning is student focused rather than teacher focused (Biggs, 1999; 2003). The strategy is also successful in aligning university courses with the real-life professional work which students are expected to undertake on graduation. At this university, plans to introduce PBL into a number of units taught in the Science Faculty were initiated in 2006, to improve student engagement and enrich the student learning experience at the first year level. This paper reports on the implementation of PBL into a core first year unit in 2007. Data for the research were gathered through student surveys and semi-structured interviews. While the implementation is perceived as a successful strategy, to achieve both aims there are still challenges, linked to group processes, to overcome. (Contains 2 tables.)