Background: Widespread concerns are being voiced in the Western world about rising rates of childbirth intervention. In Wales, United Kingdom, a Clinical Pathway for Normal Labour (Normal Labour Pathway) was devised to support normal childbirth and reduce unnecessary interventions. This study investigated the implementation of the pathway, from the perspective of midwives, doctors, and midwifery managers. Methods: An ethnographic approach was used to observe use of the Normal Labour Pathway in real life settings and evaluate its implementation. Data were collected by means of semiparticipant observation, focus groups, and interviews. Participants (n = 56) included senior practitioners involved in creating the pathway (n = 4), midwives (n = 41), managers (n = 5), and doctors (n = 6). Data were analyzed thematically. Results: Key themes related to the effect of the Normal Labour Pathway on Welsh maternity care, and midwives’ and doctors’ experiences. Midwives’ views focused on the pathway as a decision-making protocol and record of care. Recently qualified midwives were more likely to view the pathway positively than those with more experience. Doctors were critical of the pathway, experiencing it as exclusionary. Midwives and doctors considered that the Normal Labour Pathway had increased interprofessional tensions. There was no evidence that it had increased the normal birth rate. Conclusions: The Normal Labour Pathway is a complex intervention with complex outcomes. It has had intended and unintended consequences, for maternity care in general and for the roles and relationships of maternity care practitioners. The study raises questions about the appropriateness of clinical pathways and other standardized decision-making tools for the complexity of childbirth.