Background: Recent NCCN guidelines recommend the addition of a neurokinin-1(NK1) receptor antagonist (e.g. fosaprepitant) to the serotonin 5-hydroxytryptamine type 3 (5-HT3) receptor antagonist-corticosteroid combination for controlling both acute and delayed chemotherapy induced nausea and vomiting(CINV) associated with high emetogenic chemotherapy (HEC) in adults. Fosaprepitant is bioequivalent to aprepitant and could offer benefits to patients who are unable to tolerate oral antiemetics. However, little is known about the efficacy and safety of fosaprepitant in children. Methods: This retrospective chart review included all pediatric patients less than 18 years of age who received fosaprepitant at Memorial Sloan Kettering Cancer Center from July 2011 to November 2016. Results: Thirty-one patient charts representing a total of 105 doses of fosaprepitant were reviewed. Median age was 15 (range 2-17) years. Fifty-one doses (49%) were administered for primary prophylaxis for 11 patients; 40 doses (38%) for 12 patients who had a history of severe CINV and 14 doses (13%) as rescue for CINV in 10 patients after chemotherapy. Seventy-eight of the 101 chemotherapy cycles were highly emetogenic including 39 containing cisplatin. In the first two groups, patients did not have any episodes of vomiting in 97% and 88% of chemotherapy cycles respectively after fosaprepitant therapy. Seven of 12 patients receiving fosaprepitant for > 3 episodes of breakthrough vomiting within 24 hours had no vomiting episodes during the first 24 hours post fosaprepitant administration. No fosaprepitant-related side effects were reported. Conclusions: Fosaprepitant appears to be safe and tolerable in children with cancer in whom it may provide benefit as prophylaxis and treatment of CINV. However a phase III study is warranted to formally study its role in pediatrics.