The Kreek–McHugh–Schluger–Kellogg (KMSK) scale was developed to quantify self-exposure to opiates, cocaine, alcohol, and tobacco. The original study was limited by a relatively small sample that was not representative of general clinical populations, and did not include marijuana exposure. For the current study, participants were recruited from primary care outpatient clinics in an urban public hospital. The primary measure was the KMSK scale. The Structured Interview for Diagnosis for DSM-IV (SCID) was used as the “gold standard” for substance dependence diagnoses, and the results of KMSK assessments were evaluated using receiver operator characteristic (ROC) analysis. The sample (n = 439) was predominantly African American (90.6%), with mean age (±SD) of 43.1 ± 12.8 years. ROC analyses found that the optimal cutoff scores for alcohol dependence were the same as suggested previously (11), while they were lower for cocaine dependence (10 vs. 11) and opiate dependence (4 vs. 9). The analysis suggested a cutoff score of 8 for marijuana. The KMSK performed well in the current study as a brief tool for evaluating dependence on alcohol, cocaine, marijuana, and opiates in this nonpsychiatric clinic sample of predominantly poor urban African Americans. (Am J Addict 2011;20:292–299)