Preschool teachers share their environment with young children on a daily basis and interventions promoting social competence are generally carried out in the preschool setting. The aim was to find out if and how preschool teachers' definitions of social competence are related to factors in the preschool environment like: a) the number of children having problems related to social competence; b) the support provided to the children; and c) the preschool environment and current research definitions. Method: 481 preschools from 22 municipalities in Sweden participated. Data was analyzed using a mixed methods design in which a qualitative content analysis was followed by group comparisons using quantitative methods. Results: Preschool teachers defined social competence mainly as intrapersonal skills, or as interpersonal relations. The definitions of social competence were not related to the numbers of children having problems related to social skills or social competence in units, the amount of the support provided to the children or the preschool environment. Conclusion: Preschool teachers' definitions of social competence are partly multidimensional, which implies that the interventions aimed at promoting children's social skills and social competence also should be multidimensional. Preschool teachers' definitions of social competence have little relevance to environmental factors, which indicate that social competence, as a construct is more dependent upon perceptions of the individual than on contextual factors.