Consistent with the increasing national emphasis on providing health promotion in clinical care settings, Stop Smoking for OuR Kids (STORK), a research-derived, prenatal-postnatal smoking cessation intervention, was implemented throughout prenatal clinics, inpatient postpartum services, and pediatric clinics of Kaiser Permanente Northwest. Process data collected during the project rollout and maintenance to monitor the clinical practices of clinicians and staff members, patient responses to the intervention, and penetration of the intervention into the health maintenance organization priority population of prenatal smokers high-lighted barriers to intervention delivery. These barriers fell into three categories related to the smoking intervention design, clinicians and staff members, and the organization. By monitoring the intervention implementation process, such problems were identified early. This allowed for implementing strategies to overcome many of these barriers and to assess their effectiveness. Keys to implementation success included simplifying the intervention activities, considering stakeholder needs, and providing tangible organizational resources and goals.