A case of arsenic intoxication presenting as a myelodysplastic syndrome is reported. A 41-year-old woman with a 6-month history of gastrointestinal and neurological symptoms was noted to be pancytopenic at presentation. A bone marrow aspirate revealed dysmyelopoietic changes involving all three marrow cell lines. Subsequent analysis of urine for heavy metals demonstrated very high levels of arsenic. Treatment with British anti-Lewisite (BAL) resulted in the resolution of gastrointestinal symptoms and hematological abnormalities although the neurological complications progressed. This case emphasizes that heavy metal intoxication should be considered in the differential diagnosis of any individual presenting with the hematological features of myelodysplasia especially when accompanied by clinical features considered atypical for primary or secondary myelodysplasia.