**1. Introduction**

Nausea and vomiting (N/V) represents a primary issue in oncology requiring effective management for both prevention and treatment. Although in cancer patients several causes, such as opioid medications, can induce N/V, it is mainly related to antitumoral therapy. Chemotherapy-induced nausea and vomiting (CINV) is the most common and intolerable adverse event with negative impact on quality of life and treatment's adherence and efficacy. It is important to notice that large literature is available about N/V related to standard chemotherapy and little literature about new antitumoral therapies such as tyrosine kinase inhibitors, monoclonal antibodies and immunotherapeutic agents, instead. Management of N/V in cancer patients should begin with a complete assessment including evaluation of intensity and timing of appearance. To determine whether N/V is related to treatment (chemotherapy, radiation) or is independent of cancer treatment should be the second step. Various national and international antiemetic guidelines have been developed for the prevention of chemotherapy- and radiotherapy-induced nausea and emesis. The prevention of CINV is crucial to improve patients' confidence and compliance to treatments and the clinical management include both pharmacologic and nonpharmacologic therapies. This chapter addresses the epidemiology, clinical features, risk factors, mechanisms, and management of CINV.
