Little research is available on brief screening instruments for identify those meeting diagnostic criteria for drug dependence or abuse. A brief, four-item screening instrument, called the rapid drug problems screen (RDPS), was developed from a similar instrument for alcohol use disorders, the rapid alcohol problems screen (RAPS). Performance of the RDPS was evaluated against DSM-IV and ICD-10 criteria for drug dependence and for dependence or abuse in a sample of 703 emergency department patients in Mexico City. Among males, sensitivity and specificity were 91 and 96%, respectively, for dependence and 93 and 96%, respectively, for dependence or abuse. Neither of the two females meeting diagnostic criteria for dependence or abuse were identified by the RDPS. Area under the receiver-operating characteristic curve indicates an optimum cut point of 1. The data suggest that the RDPS may hold promise as a brief screening instrument for substance use among males, but should be tested in larger populations of females meeting diagnostic criteria for drug use disorders, and across ethnic subgroups in other geographic locales.