This paper discusses the development of the ERTL-4 (Epreuve de repérage des troubles du langage lors du bilan medical de l'enfant de quatre ans), a measure developed in Nancy, France specifically for the purpose of identifying children with language difficulties in the 3.9-4.6 years age range. The test has been designed to identify 10-15% of the population and allows the assessing primary care doctor to ascertain whether difficulties occur in language, voice, fluency, hearing or perception on the basis of a 5-min assessment.