The dataset contains information on the etiological and phenomenological aspects of the risk of social exclusion of children based on the assessment of preschool teachers and parents. Preschool teachers differ in their assessment of difficulties due to differences in experience with a particular difficulty, the context in which the child is assessed and differences in children’s behaviour in different contexts. These different assessments are the starting point for recognising problems, aligning expectations and planning appropriate interventions in early childhood education and care (ECEC) instututions. The following quantitative research methods were used: 1. data collection using the questionnaire to assess aetiological and phenomenological aspects of children's risk of social exclusion (versions for parents and preschool teachers); 2. data collection using the Child Behaviour Checklist by Achenbach (2000) (preschool version, CBCL/ 1½-5). The data was collected from 3,500 children. The sample is representative of the children enrolled in Croatian ECEC. The dataset was created within the Models of Response to Educational Needs of Children at Risk of Social Exclusion in ECEC Institutions (MORENEC) project, funded by the Croatian Science Foundation under grant number IP-2019-04-2011.