Rothmund-Thomson syndrome (RTS) is a genetic disease characterized by developmental abnormalities and poikilodermatous skin changes that appear in infancy. An association with myelodysplastic syndromes is rarely reported in RTS, even though impairment of immune function and recurrent infections are described in the literature. A case of Thomson-type RTS in a 14-year-old girl with trilinear myelodysplasia is presented. The patient was kept under hematologic surveillance for myelodysplastic syndrome. Bone marrow transplantation was considered unnecessary at present.