Purpose. Prenatal smoking is a preventable risk factor for poor perinatal outcomes and is more prevalent in pregnant smokers of low socioeconomic status (SES). We describe the intervention model and factors associated with quitting from the Pittsburgh STOP Program, an evidence-informed dissemination intervention for low-SES pregnant smokers. Setting. STOP is delivered in community health care clinics serving economically disadvantaged women. Participants. Participants were 856 pregnant women who were current smokers (93%) and recent quitters (7%). Most were white (59%) or black (35%), single (74%), young (mean age = 25), and experiencing an unplanned pregnancy (84%); 90% were insured by Medicaid/uninsured. Methods. An evidence-informed intervention for community pregnant women was delivered individually in a single-group pre-post evaluation design. Measures were demographics, participation and retention, smoking status, satisfaction, and cost. Analyses included descriptive statistics and logistic regression. Results. Participants attended an average of 4.7 sessions. Dropout rate after the first session was 5%. Over 11% of smokers quit; 48% of preenrollment spontaneous quitters remained abstinent. Factors significantly associated with quitting included race, mother's age, nicotine dependence, and number of sessions attended. Limitations. STOP is a community program with self-selected participants and no control group. Conclusion. Low-income pregnant smokers will engage in an evidence-informed cessation, program tailored for this group, with quit rates that compare to controlled research results. (Am J Health Promot 2011;25[5 Supplement]:S75-S81.)