Although there are numerous reports of antiarrhythmic use in children, controlled, comparison trials of antiarrhythmic agents in children are virtually nonexistent and most data are obtained from case series of children treated. Effective and safe pharmacological therapy requires that the physicians attempt to identify a drug with the most appropriate profile to attack the most vulnerable parameter of the mechanisms of the cardiac arrhythmia with the least pro arrhythmic/collateral effects. Digoxin in patients with Wolf-Parkinson – White syndrome, verapamil in infants and intravenous quinidine should be avoided as there is clear evidence that they can cause serious side effects. Collateral effects of other antiarrhythmic drugs are discussed in details in this review. Well-designed, controlled trials are needed to further evaluate the comparative efficacy of antiarrhythmics in children, as well as to evaluate dosing and toxicity in various age groups.