Roseomonas species is rarely found to be pathogenic to humans and there are few clinical cases that have been described in the literature. We report a case of Roseomonas mucosa bacteremia that involved a 9-year-old Japanese boy who was in a condition of febrile neutropenia caused by chemotherapy for cerebellar medulloblastoma. Conventional phenotyping failed to identify the organism; however, genetic analysis using 16S rDNA sequencing confirmed the pathogen to be R. mucosa. The patient recovered following treatment by meropenem without any complications. A literature review of pediatric cases of Roseomonas bacteremia identified 12 other documented cases, and these revealed that a common clinical situation for the infection is an immunocompromised state with malignancy and/or an indwelling intravenous catheter. Because of the low number of cases, the overall picture of Roseomonas bacteremia in children remains to be elucidated; however, the prognosis of the infection appears to be satisfactory.