Hematologic malignancies encompass a diverse range of diseases, such as leukemia, lymphoma, and multiple myeloma, among others. Within the multidisciplinary treatment approach, radiation therapy holds a pivotal position in effectively managing these conditions and has shown its potential to enhance local control and overall survival rates. In this chapter, we will explore and discuss the guidelines we follow to treat hematologic malignancies at our institution, with a focus on simulation techniques, indications to irradiate, and radiation doses. We will then address management of commonly encountered radiation toxicities.