In this chapter we investigate when in the child’s life the transition from parental care to care in preschool takes place in Sweden, which is characterized by publicly subsidized and universal childcare. Using register data covering the whole population, we found an increase in the age of preschool start during the 1990s followed by a trend towards earlier start in the 2000s. Children from higher income families start later than lower income families, as these parents can use the flexibility in the inter-related parental leave system to a higher extent. Minor differences are found with regard to parents’ education. Fathers’ increasing uptake of parental leave during the period explains part of the differences in education and income, as fathers with higher education and income use longer parental leave. The findings also indicate, in the later years, a trend towards a more homogeneous pattern in preschool start with regard to parents’ income, likely to be due to preschool reforms aimed at greater accessibility and pedagogical improvement.