Malignancies arising during pregnancy are an infrequent occurrence, leading to a paucity of data on the optimal management of cancers during pregnancy. Unlike most solid tumors, the primary, and often curative, management of hematologic malignancies relies heavily on multiagent cytotoxic chemotherapies over surgery and other localized therapies, making their management during pregnancy even more complex and hazardous to both mother and fetus. Close multidisciplinary care and coordination between obstetrician, maternal fetal medicine, and oncologists are essential given the dangers to both in the management, from diagnosis and throughout treatment, even through delivery and survivorship. Due to the importance of this topic and the number of lives that could be impacted, guidelines have been published by interdisciplinary expert panels based on available data and clinical experience. This review addresses the management of both Hodgkin and non-Hodgkin lymphomas as well as acute and chronic leukemias. The optimal diagnostic approaches, and therapeutic schemes, including the use of cellular therapies, immunotherapies, targeted and cytotoxic agents, as well as guidance on decision making regarding management of the pregnancy weighing both the maternal and fetal risks and benefits of each approach are discussed herein.