OBJECTIVES: Antiemetic is a drug that is effective against vomiting and nausea. The objective of this study is to calculate price trends for individual antiemetic and to describe the trends of utilization and spending on antiemetic drugs in the U.S. Medicaid program. METHODS: A retrospective descriptive analysis was performed using data from the Medicaid database from 1991 through second quarter 2011. We extracted the utilization and expenditure data from the national Medicaid pharmacy files collected by the Centers for Medicare & Medicaid Services. Study drugs include antihistamines (cyclizine, dimenhydrinate, buclizine), steroids (dexamethasone, methylprednisolone), dopamine antagonists (droperidol, ondansetron, granisetron, palonosetron).  Total prescriptions reimbursed by Medicaid and total reimbursement cost were calculated by adding the data for each antiemetic identified by its NDC. The Annual totals of reimbursement per-prescription were calculated as annual total reimbursement divided by Annual total number of prescriptions. RESULTS: The total number of prescriptions which paid by Medicaid was increased from $339,822 in 1991 to $1.0 million in second quarter of 2011. The data shows 80% decrease in antiemetic utilization in 1999. The drug Ondansetron has increasing trends after 2006 up to about 70% in the first quarter of 2011. The price was in increasing rate until 2011. About 100% increase in the price of generic Zofran. The average of reimbursement per prescription has increased from $15.22 in 1991 to $36.90 in 2011. CONCLUSIONS: In the light of this study, more studies are needed to create antiemetic guidelines that would help to improve efficacy, increase the patients compliance, and decrease the antiemetic costs.