Nausea and vomiting have been listed by patients as the most distressing side effects of chemotherapy. There are three phases of emesis associated with chemotherapy. The introduction of 5HT3 receptor antagonists revolutionised the treatment of acute chemotherapy induced emesis but had only minor impact on delayed emesis. Aprepitant, a neurokinin 1 receptor antagonist has improved the control of acute emesis when added to a 5HT3 antagonist and dexamethasone and has made a major advance in the control of delayed emesis when continued for a further two days in combination with dexamethasone. This control of nausea and vomiting associated with chemotherapy has translated into improved quality of life of the patients receiving chemotherapy. (non- author abstract)