Description: Estonia has one unite school system but about 1/6th of schools are using Russian as the language of instruction. The question about unity or differences in these two school types in educational content, quality and teaching methods is actual. Main focus in our presentation is on the comparison of Estonian and Russian language school results on reading habits and its cultural background. The main question is: are there and what kind of different teaching principles and strategies needed in situation of unite school system with two different instruction languages in multicultural society. The following sub-questions are observed: Who read more and what kind of texts, are there differences in principles and influences in choosing books, in understanding themselves as a readers, what kind of out-of-school conditions and activities are influential for reading habits and skills. The differences are also discussed in language and socio-economic context as well in light of Hall`s & Hoffstede`s theories of cultural differences. The purpose is to find out common traits and differences in children`s attitudes and learning outcomes to provide best possible instruction what takes into account as well national, language and individual differences of learners. Methodology: The Estonian Ministry of Education and Science has run national testing in 3rd grade mother tongue science 1998. From the very beginning the tests have been held in the same format both for Estonian and Russian language schools to evaluate and compare results in both school types with the same method. In 2003 a student's questionnaire was added to the national test to find social factors that may influence the literacy level. Conclusions: No general strong differences by language. Estonian language schools are doing slightly better in mother tongue tests. Gender differences are bigger than language differences Russian schools are more homogenous: smaller differences between boys and girls, in city and rural areas, by text types (narrative, expository, documents) Lower results in Estonian schools among boys, in country schools, in expository texts There are differences by instruction language what may have cultural background. By Hoffstede - Estonian language schools are more masculine and individualistic, Russian language schools have bigger power distance. By Hall - Estonian language schools have lower and Russian language schools higher context communication. Generally there is a similar structure in what children like to read and how often they read different text types.