Chronic nausea and vomiting syndrome (CNVS), one of a functional gastroduodenal disorder, was identified in an 8-year-old girl and a 13-year-old boy who had complained of nausea for more than 4 months following coronavirus disease 2019 (COVID-19) due to normality of their head computed tomography and upper gastrointestinal tract images. The patients' symptoms responded quickly to acotiamide, a medication that is effective for treating functional dyspepsia (FD). Despite being a distinct illness from FD, CNVS is also a functional gastrointestinal disorder, and acotiamide may be just as effective for CNVS following COVID-19 as for FD.