The present PhD project was conducted in the Department of Special Needs Education, Faculty of Education, University of Oslo. It is written within the field of language acquisition, with a focus on language development in language minority children, and guided by the research question: To what degree can previous language skills and contextual factors predict the development of second language skills in Norwegian language minority children? The study consisted of four smaller studies, focusing on patterns of language use, development of vocabulary, narrative production and development of listening and reading comprehension. The sample included approximately 60 children with Urdu or Punjabi as their first language, and approximately 200 children with Norwegian as their first language. The study design was longitudinal and three points of assessment were included: one assessment in the last year of kindergarten, one assessment in the first grade, and one assessment in the second grade. The assessments included a parent questionnaire, both standardized and unstandardized tests, and measures in both the first and second language. Descriptive statistics, hierarchical regression analyses and structural equation modeling were used to answer the research question. The present study supports previous research, finding large differences between the language minority and language majority children’s proficiency in Norwegian in favor of the majority language children. Moreover, the findings emphasize the importance of early language skills for both minority and majority language children, as well as contextual factors (e.g. mother’s educational level and number of books in the home). For the language minority children, contextual factors, including time spent in kindergarten, seemed to be of particular relevance. The results suggest that contextual factors should be further investigated in future longitudinal studies.