Nausea and vomiting are common adverse events in chemotherapy. In spite of the serious effects on the quality of life and further treatment, they remain overlooked by physicians, and no standard treatment has been developed. Neurokinin-1 (NK-1) receptor antagonists and palonosetron are the major agents in the standard regimen for treating moderately and highly emetogenic chemotherapy-induced nausea and vomiting (CINV). However, NK-1 receptor antagonists first became commercially available at the end of 2013 and palonosetron has not been extensively applied in China. Olanzapine was recommended as a therapy for moderate and severe CINV in antiemesis-clinical practice guidelines in oncology in 2014 for the first time. It is an atypical antipsychotic agent, which can block multiple receptors on neurotransmitters. During more than 10 years, olanzapine has demonstrated significant effects in preventing CINV and treating breakthrough and refractor CINV, which was observed in case reports, precise retrospective studies, and phase I, II and III clinical trials, with no grade 3 to 4 adverse events. In particular, it is superior to aprepitant and dexamethasone in delayed nausea and vomiting. Therefore, this compound is worthy of further investigation.