This study compared the characteristics of opioid-addicted adults seeking (n = 169) and not seeking (n = 74) methadone treatment in Baltimore, Maryland. Participants entering treatment were recruited from six methadone treatment programs, while out-of-treatment participants were recruited from the streets using targeted sampling methods. Measures included the Addiction Severity Index, a Supplemental Questionnaire, and urine drug test. Data were analyzed using ANOVA, chi(2), and regression, holding key background variables constant. Despite the lack of differences between the samples in demographic characteristics, the out-of-treatment sample reported significantly more days of heroin, cocaine, and alcohol use and spent significantly more money on drugs and earned more illegal income at baseline.