This study evaluates the difference in development of critical thinking across four groups of nurses at different stages of the academic process and their perception of their decision-making ability in practice. With the move of nurse education into institutes of higher education nationally, there are no empirical data in the UK to suggest that graduates practice any differently from their non-graduate colleagues. An opportunistic sample of 82 nurses, was chosen from recent admission on a pre-registration degree programme, to mature graduates, as well as a group of experienced, non-graduate practitioners. A quasi-experimental, between-subjects design was used. A series of one-way ANOVAs was used to analyse the difference in critical thinking across all four groups, employing the Watson-Glaser Critical Thinking Appraisal. Additionally, the Jenkins Clinical Decision-Making in Nursing Scale was used to determine the differences in decision-making ability in practice across three of the groups with clinical experience. Furthermore, a correlation was undertaken to determine what relationship, if any, existed between critical thinking and decision-making in practice. It was found that there was no significant difference in the critical thinking skills across all groups studied, supporting the findings of other studies in the USA, which examined the cognitive skills of students undertaking graduate programmes. However, in their practice, it was found that those exposed to the academic process were significantly better at decision-making than their non-academic colleagues. Finally, no relationship could be found between the development of critical thinking and decision-making in practice, suggesting that more work needs to be done to look carefully at both critical thinking skills and decision-making in practice and the tools used to measure these.