Aprepitant is a substance P/neurokinin-1 (NK1)-receptor antagonist that was approved in 2003 for prevention of CINV. In addition, updated anti-emetic guidelines that include the aprepitant regimen have been published by NCCN and ASCO. However there is scarce clinical data in Korea. The prospective study was performed to evaluate the prevention of high dose cisplatin induced nausea and vomiting in all patients who started high-dose cisplatin-based chemotherapy at our hospital. We checked the nausea severity and vomiting episodes by calling patients within 4 to 5 days after chemotherapy. The retrospective study was performed to compare the prevention of CINV in solid tumor patients who switched their anti-emesis regimen from the standard regimen to the aprepitant regimen. In aprepitant regimen, aprepitant was added to the same anti-emetic regimen used during previous cycles. We checked the nausea, vomiting grades and adverse events in electronic medical records (EMR). In prospective study, 195 patients were included in the analysis. 88.2% of patients achieved a complete response (no emesis and no rescue therapy). In retrospective study, 54 patients were reviewed. With aprepitant regimen, nausea and vomiting grades were improved in 22 patients (40.7%) and in 9 patients (16.7%), respectively. Compared with standard regimen, addition of aprepitant provided superior prevention against CINV in Korean patients receiving highly emetogenic cisplatin-based chemotherapy. Moreover, aprepitant significantly prevented CINV in patients who received the standard regimen to prevent CINV in previous chemotherapy cycles.