Our objective was to further the understanding of the process of reintegration of childhood cancer patients after treatment and to identify factors influencing that process. Using a qualitative approach, we conducted 49 interviews with parents (n = 29 mothers, n = 20 fathers) from 31 families with a child (<18 years) with leukemia or CNS tumor. Interviews were conducted about 16 to 24 months after the end of the treatment. We used a semi-structured interview guideline and analyzed the data using content analysis. Average age of pediatric cancer patients was 5.5 years at the time of diagnosis; mean time since diagnosis was 3.5 years. Parents reported immediate impact of the disease on their children. Reintegration had gone along with delayed nursery/school enrollment or social challenges. In most cases reintegration was organized with a gradual increase of attendance. Due to exhaustion by obligatory activities, reintegration in leisure time activities was demanding and parents reported a gradual increase of activity level for their children. Parents described several barriers and facilitators influencing the reintegration process into nursery/school and leisure time activities (structural support, social support, health status, intrapersonal aspects). Although many children reintegrate well, the process takes lots of effort from parents and children. Childhood cancer survivors and their families should be supported after the end of intensive treatment to facilitate reintegration.