Investment in early intervention by health visitors to support positive parent-infant relationships is a Welsh Government target. An initiative called 'Flying Start' (FS) employs health visitors to undertake intensive home visiting with families who have a new baby to promote positive family interactions. As part of this role FS health visitors utilise the Newborn Behavioural Observation (NBO) system to observe, assess, support and enhance relationships between parent(s) and child. A project was undertaken to evaluate implementation and make recommendations for future service improvement. This paper describes stage one of the project which set out to evaluate FS health visitors' views of NBO implementation by means of a questionnaire and identifies barriers and facilitating factors to its use. Stage 2 of the project was to identify how NBO use could be improved in health visiting practice, discussed in a further paper. Results revealed a majority of practitioners felt NBO implementation benefited parents and enhanced the parent-infant relationship. It was viewed as an important part of the FS health visitors' role. Barriers included lack of time coupled with chaotic home environments. Variations in practice were identified, contrary to local guidelines. Recommendations are made to enhance NBO implementation that include the development of an NBO champion to support practitioners and provide further training.