Isochromosome 5p-i(5)(p10)-represents a rare but recurrent abnormality in myeloid disorders, especially in acute myeloid leukemia. In all published cases, the isochromosome 5p was present in single copy and accompanied by one or more additional anomalies, mostly trisomy 8. Here we report a case of refractory cytopenia with multilineage dysplasia with two copies of isochromosome 5p, a single normal chromosome 5and an apparently balanced translocation between long arms of chromosome 7and 10. To our knowledge, the pentasomia 5p has never been described before the presentstudy.