There are no published reports that include both timely antemortem and postmortem carbamazepine concentrations after massive overdose. We report a fatal overdose of carbamazepine with both timely antemortem and postmortem carbamazepine concentrations. Carbamazepine concentrations were 47.7 mcg/mL 2 h antemortem and 53 mcg/mL at 9 h postmortem. The slight rise in drug concentration may reflect continued absorption of the drug in the last 2 h before death. Postmortem carbamazepine concentrations drawn from a peripheral vessel in this patient appeared to reflect drug concentrations at the time of death.