For patients receiving cancer chemotherapy, the ongoing development of antiemetic treatment is of significant importance. Patients consider nausea and vomiting among the most distressing symptoms of chemotherapy, and as new antiemetics have been very successful in prevention of vomiting, agents effective against nausea have become one of the major unmet needs. The neurokinin (NK) 1 receptor antagonist aprepitant potentiates the antiemetic efficacy of the combination of a serotonin receptor antagonist and a corticosteroid. Fosaprepitant (intravenous prodrug of aprepitant) given as a single intravenous dose of 150 mg can replace the aprepitant 3-day oral regimen. This article focuses on the development and clinical application of fosaprepitant.