Background Antiseizure prophylaxis is recommended when high-dose of busulfan is given as part of the conditioning regimens in the allogenic hematopoietic stem cell transplant. Phenytoin has been widely used but its pharmacokinetics and pharmacodynamics profile makes its use complicated. Levetiracetam is a safe, effective and well tolerated antiseizure drug with good results in epileptic patients. Objective To describe our experience using oral (p.o) levetiracetam 1000 mg every 12 h (q12h) as an antiseizure prophylaxis, evaluating its preventive effects and adverse event rates after a high-dose of intravenous (i.v.) busulfan, as part of the conditioning regimen Methods Retrospective study of patients who underwent an allogenic hematopoietic stem cell transplant with a conditioning regimen based on high-dose of busulfan between January and November 2017. Results The study population comprised 36 patients, of whom 18 (50%) had acute myeloid leukemia as diagnosis. No seizures occurred in any patient. Levetiracetam was well tolerated and no serious adverse events were reported. Conclusions Our results suggest that giving levetiracetam at 1000 mg q12h p.o starting 12 h before the administration of i.v. busulfan until 48 h after the last dose, can be used as an alternative in the prevention of busulfan-induced seizures in adults.