Activated charcoal has been shown to be an effective complexing agent for many drugs. The quantitative in vivo evidence accumulated thus far indicates that this agent can be a very valuable adjunct in the initial phases of treating acute ingestions not only in the emergency room but also as a first aid measure in the home. It is well tolerated in extremely high single doses, and there is no known contraindication to its use in treatment of acute drug ingestion. It is immediately effective upon ingestion and can be given safely by nonprofessionals; hence, its inclusion in household first-aid supplies is warranted. In the emergency room, activated charcoal can be administered by lavage tube to an unconscious patient in large and repeated doses and can be continued throughout the acute phase of the clinical illness. The effectiveness of activated charcoal can be enhanced by emesis induced by apomorphine before or after charcoal administration. Since charcoal effectively adsorbs ipecac, syrup of ipecac should be given before the activated charcoal. Although it is not uniformly efficacious for all drugs, activated charcoal appears to be a generally useful adjunct for gastrointestinal decontamination.