Myeloid disorders constitute a subgroup of hematological malignancies of myeloid lineage. In the revised 2008 WHO classification system, the nomenclature for myeloproliferative entities has been changed from "chronic myeloproliferative diseases" to "myeloproliferative neoplasms", the definition criteria has changed, and and the MDS/MPN has emerged as a well defined entity the subgroup formerly known as "myelodysplastic/myeloproliferative diseases" has changed to "myelodysplastic/myeloproliferative neoplasms". The World Health Organization classification of myeloid neoplasms relies on the association of clinical, morphologic, immunophenotypic and genetic diagnostic features. The current review highlights these changes and also provides diagnostic algorithms that are tailored to routine clinical practice.