There is robust evidence that preschool participation yields beneficial effects on cognitive, socialand emotional development, and academic achievements later on. These effects are particularlyimportant for children in poverty and at risk of social exclusion. Research shows that quality ofeducational provision matters, yet there is inconsistency in the findings on what aspects of qualitymake a difference for learning at an early age. More in-depth qualitative research is needed tounderstand the preschool learning experiences of children living in deprived situations and tounravel when the educational setting levels the playing field rather than reproduces socialinequality. Full-day preschool in the Flemish Community of Belgium is universal from 2,5 years on.Children from diverse socio-economic and ethnic groups share the same classrooms. Therefore itoffers a unique research context. We will conduct a multiple case study in 4 very diverse cases. Ineach case, a general assessment of the quality will be done and in-depth video-observations of twochildren, in interaction with teachers, peers and parents, will document their learning experiencesduring their first year in preschool. The contextualized analysis of the data will allow gaining moreinsight in the black box of children's learning experiences where quality and learning outcomes aremediated.