A major cause of maternal death in low-income countries is a lack of adequate healthcare. The dominant approach to improving care involves continuing professional development but little is known about their impact on practice. Less still is known about the determinants of practice change and barriers to implementation. This study investigated the implementation of an acute illness management course on Ugandan health professionals’ practice and determinants of practice change. Before and after training, 51 nurses, midwives, doctors and clinical officers completed tests of knowledge. Immediately post-course and 1-month later, participants completed questions assessing intention to change practice, practice and determinants of change. Post course, participants took part in focus groups. Post-course, participants reported that they were capable and were motivated to use their knowledge and skills in practice and a lower belief in opportunity to change practice. Behavioural intention was very high and behaviour 1 month later was statistically significantly lower. Three themes emerged: 1) systematic approach changing clinical practice, 2) inter-professional communication, and 3) barriers and facilitators to implementation. Educators should consider behaviour change determinants as important assessments of outcome because they provide crucial implementation of training into practice.