The definition of soft tissue and bone sarcomas include a large group of several heterogeneous subtypes of mesenchymal origin that may occur at any age. Among the different sarcomas, rhabdomyosarcoma, synovial sarcoma, Ewing sarcoma and osteosarcoma are aggressive high-grade malignancies that often arise in adolescents and young adults. Managing these malignancies in patients in this age bracket poses various clinical problems, also because different therapeutic approaches are sometimes adopted by pediatric and adult oncologists, even though they are dealing with the same condition. Cooperation between pediatric oncologists and adult medical oncologists is a key step in order to assure the best treatment to these patients, preferably through their inclusion into international clinical trials.