Pain is one of the most common and stressful symptoms in children treated for cancer in an outpatient setting. However, pain experienced by children at home is often reported too late, or not at all, to health care providers. Also, it appears that in many cases of clinically significant pain experienced in the home situation no analgesics are taken. This can be attributed to parents not wanting to bother the caregiver, not knowing who to contact and having misunderstandings about pain and pain treatment. This implementation project uses a pain monitor mobile application to monitor pain experienced by children at home. Pain scores are registered by parents (0 – 4 year olds), together (4 – 9 year olds) or by children themselves (9 – 18 year olds). When a pain score is clinically significant, the application forwards an e-alert to designated nursing specialists in the Prinses Máxima Center, after which they contact the child or parent as soon as possible to discuss pain treatment options. Aim of the project is to reduce clinically significant pain experienced by children at home, and to increase the use of pain relief in this group.