<jats:title>Abstract</jats:title> <jats:p>Hereditary gastrointestinal cancer predisposition syndromes have been well characterized, but management strategies and surveillance remain a major challenge, especially in childhood. In October 2016, the American Association for Cancer Research organized the AACR Childhood Cancer Predisposition Workshop in which international experts in care of children with a hereditary risk of cancer met to define surveillance strategies and management of children with cancer predisposition syndromes. In this article, we review the current literature in polyposis syndromes that can be diagnosed in childhood and may be associated with an increased incidence of gastrointestinal neoplasms and other cancer types. These disorders include adenomatous polyposis syndromes (APC and MUTYH), juvenile polyposis coli (BMPR1A and SMAD4), Peutz–Jeghers Syndrome (STK11/LKB1), and PTEN hamartoma tumor syndrome (PHTS; PTEN), which can present with a more limited juvenile polyposis phenotype. Herein, the panel of experts provides recommendations for clinical diagnosis, approach to genetic testing, and focus on cancer surveillance recommendations when appropriate during the pediatric period. We also review current controversies on genetic evaluation of patients with hepatoblastoma and indications for surveillance for this tumor. Childhood cancer risks and surveillance associated with disorders involving the mismatch repair genes, including Lynch syndrome and constitutional mismatch repair deficiency (CMMRD), are discussed elsewhere in this series. Clin Cancer Res; 23(13); e107–e14. ©2017 AACR.</jats:p> <jats:p>See all articles in the online-only CCR Pediatric Oncology Series.</jats:p>