We conducted a cross-sectional study using a questionnaire to explore the late effects in survivors of juvenile myelomonocytic leukemia (JMML). The attending pediatric hematologist oncologists completed the questionnaires. All survivors (N=30) had undergone allogeneic hematopoietic stem cell transplantation. Approximately 83% survivors showed more than one late effect. The identified late effects included endocrine, dental, skin, ophthalmologic, musculoskeletal, pulmonary, neurocognitive, and cardiovascular dysfunction. The prevalence of short stature and cardiovascular and kidney dysfunction was significantly elevated among survivors aged ≥18 years. Therefore, a multidisciplinary follow-up system for survivors of JMML is crucial.