Cocaethylene (ethylcocaine) (CE) was incorporated into this laboratory's urine toxicological screening protocol more than 1 year ago. During a 1-year period, 451 urine specimens tested positive for benzoylecgonine (BE) and/or cocaine (COC) and/or CE using a combination of thin-layer chromatography with enzyme immunoassay confirmation. CE was detected in 57 urine specimens. Blood ethanol (EtOH) analysis was available for 37 of these cases, and the mean concentration (1320 mg/L) was significantly higher than that found in 117 blood EtOH assays performed for the CE-negative patients (630 mg/L) (p <.01). In two instances, CE was noted in urine in the absence of EtOH in the corresponding blood. Without exception, CE, when present in urine, was always detected with both BE and COC. Most of the time, no other drugs were found. In one instance, CE was present in the urine of a neonate but was not detected in that of its mother. Demographic and analytical findings are presented for both CE-positive and CE-negative cases. © 1995, Oxford University Press.