SIOP continues to work together with CCI, IPSO and PROS as its affiliated societies, to achieve shared goals through joint projects and programmes and operational/organizational platforms.

The Paediatric Radiation Oncology Society, PROS is a SIOP collaborative society. Our ambition is to to bring together all radiation oncologists and allied professionals involved in paediatric oncology.

The International Society of Paediatric Surgical Oncology is a SIOP collaborative society. IPSO is an international society of surgeons who specialise in the surgical care of children with cancer.

Childhood Cancer International (CCI; formerly International Confederation of Childhood Cancer Parent Organizations) was founded in 1994, as an umbrella organization of childhood cancer grassroots and national parent organizations.