Gabapentin is well known for its pain control and antiepileptic effect, but its antiemetic effect is poorly investigated. Here we report on effective gabapentin use for refractory vomiting after craniotomy in two children with medulloblastoma in the fourth ventricle. The two pediatric patients (an 11-year-old girl and a 4-year-old boy) underwent near-total excision of the tumor via craniotomy. Both patients suffered from refractory postoperative nausea and vomiting, treated with multiple traditional antiemetic drugs but without relief. After gabapentin intake, their nausea and vomiting improved from one to two episodes per day to complete resolution of symptoms. This report suggests that gabapentin may be a novel antiemetic therapeutic intervention for patients with refractory nausea and vomiting after craniotomy.