The aim of this study is to measure and evaluate the moral reasoning of undergraduate pharmacy students as they progress through a British university, and onward through the early years of their professional practice. This study utilizes version 2 of Rest's Defining Issues Test in a longitudinal design, evaluating a single cohort of future pharmacists, which started a 4-year Master of Pharmacy degree program in 2008-09, completed their preregistration training, and progressed through their early careers. The final dataset was collected in 2019. Both descriptive and inferential statistical analysis was subsequently carried out. The cohort experienced significant moral growth during the 4 years of their undergraduate degree, where they were exposed to an ethical education designed to engage students at the "plus one" level of moral reasoning. There is also evidence for work-based augmentation of moral development between graduation from university and qualification as pharmacists. The subjects underwent a marked increase in moral development as they progressed through their undergraduate studies, followed by another sizeable, though not statistically significant developmental progression during the preregistration year. The retrograde step in moral development observed between newly qualified level and established practitioner level requires further investigation: structured interviews with participants, which focus on changes to their experiences in practice and how these affected their moral agency are already underway.