Background/Aim: As the knowledgebase of acute myeloid leukemia (AML) has grown, classification systems have moved to incorporate these new findings. Methods: We assessed 32,941 patients with AML whose records are contained in the Surveillance, Epidemiology, and End Results (SEER) database. Results: Half of all patients diagnosed between 2001 and 2013 did not have a World Health Organization (WHO) classification. Acute promyelocytic leukemia and acute panmyelosis with myelofibrosis were associated with the longest leukemia-specific survival (110 and 115 months, respectively), and AML with minimal differentiation and acute megakaryoblastic leukemia with the shortest (30 and 28 months, respectively). For patients in the WHO groups AML not otherwise specified (AML-NOS) and AML with recurrent genetic abnormalities (AML-RGA), the risk of death was greater for older patients and less for married patients. Black patients with any type of AML-NOS also had a higher risk of death. Patients whose case of AML did not receive a WHO classification were older and this group had a higher risk of death when compared to patients with a WHO type of AML-NOS. Conclusion: Our findings highlight the divergent outcomes of patients with AML and the importance of using the WHO classification system and demographic factors to gauge their prognosis.