The pharmacokinetics of aminosteroid neuromuscular blocking drugs have been shown to be altered in patients with hepatic cirrhosis. A reduced clearance and prolonged elimination half-life of pancuronium and vecuronium have been demonstrated. Pharmacokinetic studies of the newest aminosteroid neuromuscular blocking agent, rocuronium, performed in a small number of cirrhotic patients, have proved inconclusive, apart from noting a higher central volume of distribution than in healthy patients. This difference may result in a slightly delayed onset of neuromuscular block. Nevertheless, rocuronium, even in cirrhotic patients, has the fastest onset of action of any non-depolarizing neuromuscular blocking agent. Further pharmacokinetic studies are necessary of this drug in hepatic cirrhosis.