Aim: To assess nurses’ ability to observe newborn behaviour after in situ training provided by caregivers with advanced practice certification in the Newborn Individualized Developmental Care and Assessment Program (NIDCAP). Design: Prospective observational study. Methods: Twelve nurses viewed 20-min films showing the behaviour of 10 premature newborns before, during and after the usual caregiving. The behaviour was rated on an observation sheet with 88 items distributed into six systems. The responses were compared to the reference ratings established by two professionals certified for this programme. Results: Despite less accurate observations during care and for some components, the nurses generally showed a satisfactory ability to observe newborn behaviour after training by NIDCAP expert professionals. The dissemination of observation skills among caregivers may result in an improved quality of patient care and better communication among professionals in a department of neonatology.