Lidocaine, as an example, is frequently used as an antiarrhythmatic agent and is well documented as having anticholinergic activity among its side effects. We have seen numerous cases of acute onset of delirium following the parenteral injection of lidocaine and treated successfully with physostigmine while consulting at Cardiac Care Unit. We would like to present 4 cases of lidocaine induced delirium that were successfully cleared up with the repeated low dosage injections of physostigmine salicylate (Antilirium). Physotigmine is an anticholinesterase agent that can pass the blood-brainbarrier, thus capable of re-establishing the balance of central cholinergic activity in the brain. Due to its cholinergic adverse effects in overdose that might cause danger to seriously ill medical and surgical patients, its use in drug-induced delirium is avoided by most clinicians. Our approach to this issue is to give low dosage (0.4mg–0.5mg) of physostigmine I.M. or I.V. repeatedly every 1.5–2 hours thus avoiding the possibility of overdose and still achieving the therapeutic goal of clearing up anticholinergic induced delirium in a short period of time. We will discuss further in detail the literature and clinical significance of our work in the report.