Myelodysplasia associated with a complex karyotype is usually associated with advanced stage myelodysplastic syndrome (MDS) and an enhanced risk to develop secondary leukemia. We report on a 36-year-old female patient who was first presented in 1997 because of 'Pseudo Pelger-Huet' neutrophils. The remaining blood and differential counts were normal. Bone marrow examination revealed dysplasia in the erythroid and granulocytic series, no increase in blasts, and a karyotype with complex aberrations involving chromosomes 7, 13, 20 and 22. Almost all metaphases examined appeared to be affected. During the next few months, the patient was closely monitored and considered as candidate for bone marrow transplantation. However, blood counts remained stable without occurrence of significant cytopenias or an increase in blasts. Re-examinations of the bone marrow in 1998 and 1999 disclosed identical results compared to that obtained in 1997. After a total follow up of 6 years, the patient is still in good health with normal blood counts and persisting 'Pseudo Pelger-Huet' neutrophils. This exceptional case supports the notion that complex chromosomes are not invariably associated with rapid disease evolution in MDS.