Cigarette smoking intensifies a number of serious health problems, including lung cancer, hypertension, low birth weight, and infant mortality, that disproportionately affect black Americans. Cotinine, a major nicotine metabolite, is one indicator of smoke exposure. It has been reported that black women have higher mean cotinine levels than white women. This divergence may be attributed to biologic factors or to inaccuracy in reporting cigarette use. The purpose of this study was to characterize nicotine dependence and the relationship between self-reported cigarette use and cotinine levels among black women smokers. The sample consisted of 142 black women cigarette smokers recruited individually at urban health centers and worksites. A cotinine/cigarette ratio was determined for light, moderate, and heavy smokers. Underreporting of cigarette consumption, previously defined as cotinine value > 25 ng/ml/cigarette, ranged from 86% among light smokers to 70% among moderate smokers and 21% among heavy smokers. There were significant differences in cotinine/cigarette and nicotine dependence scores across levels of smoking. Average cotinine/cigarette values were higher in black women compared with previous reports for Mexican American women smokers. No comparable values are available for white women. Additional study is needed to begin to explain variations in levels of cotinine, as well as perceived nicotine dependence among black women.