Objective: To evaluate cases of suspected drink spiking presenting to the ED by the prospective collection of standardized relevant historical, clinical and laboratory data.Methods: A prospective observational study of 101 patients presenting to metropolitan hospital ED with suspected drink spiking within the previous 12 h. Clinical history, including details surrounding the alleged drink spiking incident, and examination. Blood ethanol concentration measurement, together with the analysis of urine and blood samples for illicit and sedative drugs.Results: Of the 97 alleged drink spiking cases included, there were only 9 plausible cases. We did not identify a single case where a sedative drug was likely to have been illegally placed in a drink in a pub or nightclub. Illicit drugs were detected in 28% of the study group. Ethanol was commonly detected, with the mean number of standard drinks consumed being 7.7 ± 3.9 SD, and the median blood ethanol concentration at the time of presentation was 0.096% (96 mg/dL). At follow-up there were no major sequelae and no police prosecutions. Thirty five per cent of patients still believed that they had been a victim of drink spiking irrespective of the results.Conclusion: Our study did not reflect the current public perception of drink spiking. Drink spiking with sedative or illicit drugs appears to be rare. If drink spiking does occur, ethanol appears to be the most common agent used. Of greater concern was the frequency of illicit drug use and excessive ethanol consumption within the study population, making it difficult to determine whether a person had truly had a drink spiked.