The authors describe the Marijuana Treatment Project used to guide this research. Conducted at 3 community-based substance abuse outpatient treatment facilities in Florida, Washington, and Connecticut, this study examined the differences between the 450 adult marijuana abusers who initiated substance abuse treatment and the 363 individuals who declined treatment for their drug problems. Examining program participants’ and program decliners’ demographic characteristics, residential stability variables, employment and educational histories, referral sources, and information gathered through screening interviews, the authors conducted stepwise logistical regression in order to confirm variables associated with treatment initiatives in bivariate analyses. The authors found that pre-treatment drop-out was linked to substance abusers that were younger in age, unmarried, unemployed, less educated, and of Asian American or Native American descent. The authors also found that pre-treatment drop-out rates were associated with a lack of self-perceived dependency on marijuana and the use of other drugs. The authors conclude that only by recognizing the demographic and substance use factors that serve as barriers for marijuana abusers receiving treatment will clinicians be able to effectively target clients with the characteristics linked with dropping out of drug treatment programs. Tables, references