© 2015, Springer-Verlag Berlin Heidelberg. Introduction: Olanzapine is an atypical antipsychotic drug that inhibits serotonergic, dopaminergic, alpha-1 adrenergic, histaminic, and muscarinic receptors. Several phase I and II trials have been published documenting the use of olanzapine in controlling chemotherapy-induced nausea and vomiting (CINV). This review aims to summarize all phase I and II trials that reported on olanzapine for the prophylaxis of CINV. Methods: A literature search was conducted in Ovid MEDLINE from 1946 to July week 1 2015, Embase Classic and Embase from 1947 to 2015 week 28, and the Cochrane Central Register of Controlled Trials up until June 2015. Phase I and II trials reporting on olanzapine for the prophylaxis for CINV were included if they reported on at least one of four primary endpoints: complete response (CR), complete control (CC), no nausea, and no emesis. Other endpoints of interest included the safety of olanzapine as measured by the M.D. Anderson Symptom Inventory. Results: Across the seven included studies, there were a total of 201 patients. The CR across four studies was 97.2, 83.1, and 82.8 % for the acute, delayed, and overall phases, respectively. The CC for acute, delayed, and overall phases was 92.5, 87.5, and 82.5 %, respectively. The overall no nausea rate was 92.7, 71.8, and 70.6 % for the acute, delayed, and overall phases, respectively. The overall no emesis rates for the acute, delayed, and overall phases were 100, 94.5, and 90.4 %, respectively. Fatigue, drowsiness, and disturbed sleep were common side effects. Conclusion: Olanzapine is efficacious and safe when used as a prophylaxis for CINV.