Abstract The development of the Preschool Behaviour Checklist, for screening emotional and behavioural problems in preschool children in group settings, is described. Inter-rater reliability and internal consistency was established, and its validity was shown using a variety of methods. These include observations of the children, interviews with staff, comparison between clinic and nonclinic populations, factor and cluster analysis and comparison with another screening questionnaire. Uses of the PBCL for training and in service work are outlined. The limitations of screening as a method of identifying children with behaviour problems are discussed.