Aim: High-dose valproic acid (VPA) improves the survival and neurologic outcomes after asphyxial cardiac arrest (CA) in rats. We characterized the pharmacokinetics, pharmacodynamics, and safety of high-dose VPA in a swine CA model to advance clinical translation. Methods: After 8 min of untreated ventricular fibrillation CA, 20 male Yorkshire swine were resuscitated until return of spontaneous circulation (ROSC). They were block randomized to receive placebo, 75 mg/kg, 150 mg/kg, or 300 mg/kg VPA as 90-min intravenous infusion (n = 5/group) beginning at ROSC. Animals were monitored for 2 additional hours then euthanized. Experimental operators were blinded to treatments. Results: The mean(SD) total CA duration was 14.8(1.2) minutes. 300 mg/kg VPA animals required more adrenaline to maintain mean arterial pressure ≥80 mmHg and had worse lactic acidosis. There was a strong linear correlation between plasma free VPA Cmax and brain total VPA (r2 = 0.9494; p