We opt for a cross-national analysis to address two sets of research questions: (1) Is preschool attendance positively associated with reading competencies at later stages of children's schooling experience? Is this positive association more pronounced in countries with more favorable preschool characteristics? (2) Do children from a disadvantaged social background benefit more from preschool attendance in terms of reading competencies than children from an advantaged social background? And is this more pronounced in countries with more favorable preschool characteristics? To answer these questions, we opt for a macro-level analysis of 14 developed countries combined with a more detailed examination of selected countries that are as diametrically different as possible in terms of their preschool programs. In order to classify preschool systems, we shall focus on the time intensity of attendance and the quality dimension, because these characteristics can be particularly important for cognitive stimulation and development. (author abstract)