Abstract The Swedish society has always been monolingual, but has for the past decades transformed into a multicultural and multilingual society. The aim of this study is to investigate if and in that case how preschool teachers work with language development in bilingual and multicultural preschools. The concept of linguistic and cultural diversity includes several different components, not least the social interactions that are of great importance to every individual's development, learning and participation in the world. By understanding the importance of language, language development and the role of mother tongue in second language acquisition, we look into various researches done concerning the effects of the preschool teachers’ opinions, methods used to language developmental primarily for children who are multilingual and how the physical environment is shaped to promote language in multicultural and multilingual preschools. The method used in this study is semi-structured interviews with preschool teacher working in multicultural or bilingual preschool settings. The questions concerns opinions on multilingualism, which methods are used to promote children´s second language acquisition and development, and also how the physical environment is shaped to influence children´s cultural and lingual backgrounds in the preschools. The results are analyzed through the socio-cultural perspective, the curriculum for preschool, language acquisition theories, language and second language development and prior research in the studies three areas, opinions, methods and the physical environment. Regarding the preschool teachers opinions about multilingualism the results shows that knowledge of the child’s mother tongue, culture and background is of importance when working with children from a multicultural and multilingual background. The preschool teachers express a need for further education and knowledge of multilingual children’s language acquisition and development. Furthermore the results shows that preschool teachers point out that literature conversations is the most common methods as well as TAKK (sign as a complement for communication). Concerning how the preschools physical environment is shaped the results shows that such is not the case. The children's different experiences often get little or no space in the preschools physical environment primarily in terms of creating an environment that is recognizable for children from a linguistic and cultural diverse background. The discussion about the results stresses the need of further research and deeper knowledge among the preschool teachers concerning methods used and the importance of ensuring that the preschools physical environment reflects the children’s different cultures and languages. Keywords: Multilingualism, Second language acquisition/ development, Place identity Socio-culture perspective, Preschool Nyckelord: Flerspråkighet, Andraspråks inlärning/ utveckling, Platsidentitet Sociokulturellt perspektiv, Förskola