The authors estimate contribution of different factors in reading skills of 15?year-olds by using four models of multilevel regression analysis. It turned out that the most significant factor is family background — not only at the individual level, but at the school level as well (average school socio-economic status of schoolchildren families effects average reading skills). At the school level the aggregated family characteristics of students affect individual achievements, and this effect surpasses an effect of school resources and localization of schools — those school factors that show a significant contribution to achievement. Attitudes toward reading and learning are significant at the individual level, but at the school level children’s attitudes toward reading and school don’t make an independent contribution to the individual results.