Even today, nausea and vomiting are two of the most distressing adverse effects associated with tumor therapy. The authors give an overview of the mechanism and the trigger factors (emetogenic potential of the chemotherapies, the patient risk factors, and the used antiemetic drugs) of nausea and vomiting. A short summary will describe the antiemetic drugs focusing on metoclopramide, steroid and the currently widely used setron therapy which is effective only during the acute phase of chemotherapy-induced nausea and vomiting (CINV). In the treatment of CINV the latest improvement was the introduction of the neurokinin (NK1) receptor antagonist class. Currently the only available agent is aprepitant which is indicated to treat CINV in case of highly and moderately emetogenic chemotherapies. The pivotal phase III trials defined that aprepitant is the first drug that is able to protect against the delayed phase of CINV plus can improve the antiemetic therapy during the acute phase. Currently aprepitant is reimbursed in Hungary only after the failure of setron therapy in case of high dose (\>50 mg/m2) cisplatin protocols. The authors give a recommendation how to treat CINV based on the latest international antiemetic guidelines.The mechanism and the trigger factors of radiotherapy-induced nausea and vomiting (RINV) are different from CINV. For treatment of RINV metoclopramide (due to reimbursement regulation) and ondansetron can be used. In case of radio-chemotherapy the antiemetic treatment should follow the CINV guidelines.