Toxicities and medical outcomes associated with nefazodone poisoning were characterized using national poisoning data from the American Association of Poison Control Centers and through prospective collection of additional data elements. Nefazodone exposures involving concomitant agents were excluded. There were 1,338 human exposures included in the final data analysis. Seventy-five percent of exposures were acute and 20% involved children < 13 years. Twenty-five percent of patients remained asymptomatic. There were no deaths. No dose response relationship was evident in the 45 cases where estimated doses were available. The most common manifestations were drowsiness (17.3% of all patients), nausea (9.7%), and dizziness (9.5%). The most common serious clinical effect was hypotension (1.6%). The median onset time for symptoms was 1.75 hours. Manifestations resolved within 8 to 24 hours. Most patients were treated with only gastrointestinal decontamination. No patients required intubation, mechanical ventilation, or vasopressors. Nefazodone appears to be of low toxicity during poisonings.