Self-esteem, depression and anxiety were investigated in 51 Swedish children and adolescents, 8-18 y, on (n = 16) and off (n = 35) cancer treatment. The self-report measures "I Think I Am" (ITIA), the Children's Depression Inventory (CDI) and the Revised Children's Manifest Anxiety Scale (RCMAS) were used. Data were compared with data previously obtained by others for healthy Swedish children. Children and adolescents on treatment showed levels of self-esteem, depression and anxiety comparable to those of healthy children. However, children and adolescents off treatment reported higher depression and anxiety levels and lower psychological well-being and physical self-esteem than have been reported for healthy Swedish children. Seven children (14%) reported a high level of depression, six of whom were off treatment. The findings suggest that the period after treatment termination is characterized by a higher risk of psychosocial problems than is the actual treatment period.