We report our experience with oral busulfan (BU) in 159 consecutive patients to evaluate the safety of home administration. Patients received a myeloablative BU-containing regimen, including oral anticonvulsant and antiemetic prophylaxis, followed by hematopoietic stem cell transplantation. Comprehensive verbal and written education was provided. Pharmacokinetic monitoring was performed and dose adjustments were made to target an area under the plasma concentration-time curve (AUC) of 900-1500 micromol.min/l. Safety was assessed by evaluating therapy-related toxicities, including seizures, venoocclusive disease (VOD) and patient tolerability. The utilization of pharmacokinetic monitoring was reviewed as a secondary end point. Of the 143 patients evaluated for BU-related seizures and VOD, only two (1.4%) experienced a generalized seizure and four patients (3%) were diagnosed with VOD. VOD resolved in three patients and was a contributing cause of death in one patient. Additional BU dosing owing to nausea and/or vomiting occurred in 28 patients (18%) and five patients (3%) were hospitalized. The median measured AUC was 1405 micromol.min/l, 68% of patients required a dose adjustment, and the median total administered BU dose was 13.6 mg/kg. In conclusion, high-dose oral BU can be safely administered on an outpatient basis.