This two PHASE evaluation documented the delivery and effectiveness of evidenced-based health education methods by regular staff to pregnant smokers. During PHASE 1, 436 Medicaid patients were screened and 416 (95%) gave consent: 334 non-smokers and 102 smokers. This historical Comparison (C) group was assessed to document the “normal” pre-Trial smoking prevalence, patient non-disclosure (deception), and cessation rates at the 1st prenatal visit and during care. After this study, a Formative Evaluation of SCRIPT methods was conducted among 139 Experimental group patients and 126 Control group patients. During the PHASE 2, 6514 patients were screened over a 36 month period: 1736 (27%) were smokers and 1340 (77%) gave consent. After randomization, 247 became ineligible. The remaining 1093 smokers received brief routine advice to quit. The Experimental group (N=544) also received: a “Commit To Quit” video, “A Pregnant Woman’s Guide to Quit Smoking”, and counseling. Self-reports and saliva were collected at baseline, ≥ 60 days, and ≤ 90 days postpartum for cotinine analyses to document cessation and significant reduction (SR) rates. The PHASE 1 Formative Evaluation documented a 24% non-disclosure rate at the onset of care. It also confirmed a significantly higher Experimental (17.3%) versus Control group (8.8%) cessation rate and Experimental versus Control group SR rates of 22% and 16%. During PHASE 2, unplanned policy changes, and delivery of E group counseling procedures to 15%–20% of C group patients, resulted in a final E group cessation rate of 12% and C group rate of 10%. The E group SR rate of 18%, however, was significantly higher than the C group SR rate of 13%. Effectiveness varied by the stability of clinic infrastructure, and degree of fidelity of staff performance of assessment and intervention procedures. The methods and results of this study will assist future health education programs for pregnant smokers to plan and conduct process and impact evaluations in prenatal care.