Copper deficiency associated with neurological disorders is a well-documented condition. However, hypocupremia is less often recognized as a cause of cytopenias or bone marrow failure. We report an illustrative series of three new cases of bi-lineage cytopenia associated with copper deficiency. We have analyzed clinical features of current and historical cases to identify clues that could facilitate application of appropriate laboratory testing and heighten the level of clinical suspicion. By maintaining an appropriately high level of suspicion for potential copper deficiency and obtaining a serum copper level, bone marrow failure due to this condition can be correctly diagnosed and treated. We suggest that copper deficiency be included in the differential diagnosis of reversible causes of bone marrow failure syndromes including myelodysplastic syndrome.