The purpose of this study was to determine if emergency medical services (EMS) providers routinely initiate field gastrointestinal decontamination of adult drug overdose patients transported to the emergency department (ED). A retrospective prehospital chart review was performed on adult patients identified as drug overdose who were transported by EMS. ED charts on patients transported to a university hospital were reviewed for follow-up data. Prehospital care records showed that gastrointestinal decontamination was initiated in only 6 of 361 (2%) patients, all of whom received ipecac. No patient received activated charcoal. The median transport time was 25 minutes (range, 5 to 66 minutes). Follow-up data on patients transported to the university hospital revealed that 30 of 43 (70%) patients who might have been suitable candidates for prehospital activated charcoal actually received activated charcoal in the ED. Median time to activated charcoal in the ED was 82 minutes (range, 32 to 329 min). Use of activated charcoal in the field appears to be deferred despite its known loss of efficacy over time. The failure to start activated charcoal in the field contributes to the delay in initiating activated charcoal therapy.