At a time when inclusion is valued, an important question is how it can be put into practice. This study investigates how one Swedish preschool and one of its units achieve inclusion. It adopted a mixed method research approach and a case study design. Participating in the study were one head teacher, five preschool staff members and five children with attachment difficulties/an attachment disorder. The data were collected by way of structured and semi-structured observations, a focus group interview and one retrospective interview. Thematic and statistical data analyses as well as pattern-matching were conducted. The study shows that preschool inclusion was achieved by means of a new unit, a specialised organisational typology, full inclusion, a two-tiered system of integrated support, a shared vision, high expectations of all children, positive attitudes, qualified staff, staff support and sufficient funding as well as a set of factors and inclusive practices that were implemented to a high level of quality (nearly excellent; m = 6 on a 7-point Likert Scale). The pattern of the results, with two exceptions, supports the predicted pattern with a basis in previous studies and frameworks. The study answers the question and can form a basis for interesting discussions.