The present study has utilized a clinical model to compare the pharmacokinetics of four currently available amide local anaesthetic agents in theoretically equipotent concentrations. In addition to providing comparative data concerning the onset and duration of analgesia, anaesthesia, paresis, and paralysis, it has provided definitive confirmation of the clinical impression that under certain circumstances following the performance of a nerve block, motor blockade may actually precede sensory blockade, and an explanation for this seeming violation of established neurophysiological principles has been postulated. The study has also raised questions concerning the sequence of recovery from motor and sensory blockade which still await explanation.