Sugammadex is a new molecule derived from a known pharmacological class : the cyclodextrins known and used in human for many years. It was recently demonstrated that cyclodextrins could encapsulate and bind strongly steroidal neuromuscular blocking agents. Among cyclodextrins gamma-cyclodextrins proved to be more efficient. The binding of cyclodextrins to rocuronium and compound's water solubility was greatly improved by addition of 8 side chains to glycopyranoses units and the presence of a negative charge to the end of these side-chains. Animal studies have clearly demonstrated that sugammadex is faster in onset than anticholinesterase agents and is specific of steroidal neuromuscular blocking agents. It cannot reverse neuromuscular block induced by succinylcholine or benzylisoquinolines such as atracurium or cisatracurium. In human, the dose of sugammadex required to reverse shallow block is 2 mg/kg approximately whereas 4 mg/kg is needed to reverse deep level of neuromuscular block with a few responses at the post tetanic count at the adductor pollicis. The use of sugammadex was not associated with recurrence of block when an adequate dose was administered.