We present a case of juvenile myelomonocytic leukemia (JMML) with ocular infiltration. A 1-month-old boy presented with myeloid precursors in peripheral blood and a white blood cell count  1 10×10⁹/l. His peripheral blood monocyte count was  1 1×10⁹/l, bone marrow blasts were <20%, and no Ph chromosome was identified. The boy also presented with hepatosplenomegaly, pallor, fever, and skin rash. We diagnosed this case as JMML, although hemoglobin F was within the normal range and no spontaneous colony growth was observed from peripheral blood mononuclear cells. Neither Epstein-Barr (EB) virus nor cytomegalovirus was detected by PCR in bone marrow aspirate or peripheral blood. The patient had several lesions into which JMML cells might have infiltrated, including skin, liver, spleen, oral cavity, right lung, sigmoid colon, and both eyes. To our knowledge, this is the first reported case of JMML with ocular involvement. Since infiltration of JMML cells into both eyes causes blindness, further consideration of the timing of bone marrow transplantation (BMT) in JMML is necessary.