Myelodysplastic syndromes/myeloproliferative neoplasms (MDS/MPN) comprise a spectrum of myeloid disorders with both dysplastic and proliferative features, arising from hematopoietic stem cells. MDS/MPN are neither MDS nor MPN but a distinct World Health Organization-defined subclassification of diseases that, by definition, do not arise from a pre-existing MDS or MPN, inherently creating diagnostic and therapeutic challenges. Appropriately recognizing and classifying MDS/MPN is paramount for appropriately formulating treatment strategies and accurate prognostication. Highlighting the unique molecular, morphologic, and clinical characteristics among the subclassifications of MDS/MPN can assist in the appropriate diagnosis and aid in choice of therapeutic strategies. We describe the challenges of the appropriate diagnosis and treatment of MDS/MPN.