Nausea and vomiting are common adverse events in chemotherapy. In spite of the serious effects on thequality of life and further treatment, they remain overlooked by physicians, and no standard treatment has beendeveloped. Neurokinin-1 (NK-1) receptor antagonists and palonosetron are the major agents in the standardregimen 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 palonosetronhas not been extensively applied in China. Olanzapine was recommended as a therapy for moderate and severeCINV in antiemesis-clinical practice guidelines in oncology in 2014 for the first time. It is an atypical antipsychoticagent, which can block multiple receptors on neurotransmitters. During more than 10 years, olanzapine hasdemonstrated significant effects in preventing CINV and treating breakthrough and refractor CINV, which wasobserved in case reports, precise retrospective studies, and phase Ⅰ, Ⅱ and Ⅲ clinical trials, with no grade 3 to4 adverse events. In particular, it is superior to aprepitant and dexamethasone in delayed nausea and vomiting.Therefore, this compound is worthy of further investigation.