Cocaine is a powerful reinforcer that has become a popular drug of abuse. Cocaine inhibits the reuptake of dopamine into presynaptic terminals, resulting in an overstimulation of the dopaminergic system. When cocaine and alcohol are taken together, cocaine is partially converted by a liver carboxylesterase to its ethyl homolog called ethylcocaine. In 1991, several studies demonstrated that ethylcocaine is a pharmacologically active metabolite of cocaine. Ethylcocaine was shown to be even more potent than cocaine in mediating lethality. In the USA, prevalent studies have indicated that concurrent and simultaneous abuse of cocaine with alcohol were a very common practice. In Switzerland, as far as we know, epidemiologic studies have not been carried out yet. In our laboratory, radioimmunoassays mainly sensitive to benzoylecgonine (an inert metabolite of cocaine and ethylcocaine) are used to detect cocaine abusers. Positive results are always confirmed by combined gas chromatography (GC) and mass spectrometry (MS). Recently, cocaine, ethylcocaine, methyl ecgonine and ethyl ecgonine were detected by GC/MS in urine from three people arrested after erratic driving. Their blood alcohol concentration was 2.89, 0.98 and 1.26 g/kg. In Switzerland, the influence of alcohol, cocaine and ethylcocaine on the incidence of accidents, overdose and death is not known and requires further studies. Because morbidity and mortality are exacerbated by concurrent use of alcohol and cocaine, physicians should discourage their hooked patients from consuming this deadly mixture.