Busulfan and etoposide have been used as preparative therapy for autoSCT (stem cell transplant) in adults with acute myeloid leukemia (AML) at UCSF for the past 10 years. Over this period and together with collaborative transplant centers, over 200 patients have received this treatment. By intent-to-treat analysis, and with median follow-up of 7.0 years, the 5-year DFS is 55%. The current protocol will utilize the combination of IV Busulfan (BU) and etoposide. The busulfan dose will be escalated amongst 3 targeted dose levels. All targeted dose levels represent higher busulfan dosing than standard myeloablative dosing, with the lowest dose being approximately 14% higher than standard. Busulfan levels will be monitored after the first, fourth and twelfth doses. Dose adjustments will be made "in real time" based on AUC levels determined from the first and fourth doses. This strategy of busulfan monitoring and dose adjustment has improved the therapeutic widow of BU in previous clinical trials.