A 31-y-old epileptic man developed coma and shock after suicidally ingesting large amounts of valproic acid and gabapentin. His peak valproic acid, level was 1306.9 micrograms/mL (therapeutic range = 30-100 micrograms/mL). His peak gabapentin level was 60.0 micrograms/mL (therapeutic range = 2.0-8.0 micrograms/mL). His hypotension was refractory to crystalloid and pressor infusions, but resolved during concurrent hemoperfusion and hemodialysis to enhance elimination of valproic acid. Concurrent hemoperfusion and hemodialysis, in series, produced a maximum valproic acid plasma clearance of 55.4 mL/min versus a maximum reported intrinsic valproic acid plasma clearance of 10.6 mL/min. concurrent hemoperfusion and hemodialysis, in series, should be considered in hemodynamically unstable patients with valproic acid poisoning whose clinical condition is worsening in spite of aggressive supportive care.