The aim of this study was to analyze our liver transplant patients who had tacrolimus (TAC) related seizure in the early postoperative period. Liver transplantation (LT) was performed in 133 patients between September 2001 and June 2006. All received a TAC based immunosuppressive protocol after LT. Twelve (9%) of those 133 patients had seizure in the first month (female/male= 1/11, mean age 20±12 years, range, 12 to 49 years). Three of these patients received grafts from cadaveric donors and 9 from living donors. All patients presented with generalize tonic-clonic seizures. Most had minor forerunner symptoms just hours before the attack. Blood tacrolimus levels were within the therapeutic levels, and there were no other reasons that could initiate a seizure at that time. Post-seizure magnetic resonance imaging revealed any abnormality. TAC was converted to cyclosporine in 11 patients and to rapamycine in 1, besides antiepileptic therapy. All patients recovered and seizures disappeared. There was no nephrotoxicity or vascular complications related to drug conversion. Death unrelated to seizure occurred in one patient 2 months after LT. Eleven patients are alive with good graft function during a mean follow-up of 20 +/- 19.7 months (range, 1-52 months). In the early post-transplant period each neurologic disturbance even the minor ones should alert the clinician as they might be a warning message for a coming seizure. These patients should be followed closely and the clinician should not hesitate for a drug conversion in suspicious cases.