This article draws on a research project, funded by the Nuffield Foundation, looking at early years professionals' knowledge about speech and language development and their confidence and skills in assessing normal and delayed language development. Key findings, based on 829 questionnaires and 50 interviews, reveal very limited training in speech and language difficulties as part of initial training and low levels of post-qualification training in children's speech and language. Practitioners are aware of the need for early identification of children's communication difficulties but lack the tools with which to perform this identification. In order to provide a context for these results, a content analysis of the curricula from a variety of initial training routes explored the extent to which there was a focus explicitly on assessment and identification of children with speech and language difficulties. The role of professional journals and key texts in supporting practitioners in making judgements about children's language development was also investigated. The access to, and provision of, post-qualification training to support the assessment process is identified as a key area for development.