We report a case of acute myeloid leukemia with myelodysplasia-related changes in a patient with Crohn's disease. The patient was diagnosed with Crohn's disease at the age of 47 years and was treated with the tumor necrosis factor α inhibitors adalimumab and infliximab, and a short course of azathioprine. Four years later, the patient developed acute myeloid leukemia with myelodysplasia that involved mainly erythropoiesis. Crohn's disease is associated with an increased risk of cancers including hematological malignancies. Cancer surveillance including hematology assessment is warranted to monitor the patients on immunosuppressive therapy.