The study aimed to reduce women's exposure to passive smoking, which has been linked to increased risk of cancer and other diseases. By exploring the knowledge, attitudes and behaviors of pregnant women with regard to secondhand smoke in the home environment, a model for intervention during the pregnancy was designed with the help of the intended beneficiaries and was piloted. The study had two phases. Phase 1 included focus group discussions and an iterative process to design an intervention. Phase 2 was the intervention itself, which included a series of motivational and patient communication activities, a resource booklet, clinician counseling, telephone hotline and regular telephone counseling. Pre- and post-intervention questionnaires were used to measure results. Post-intervention questionnaires showed a significant increase in knowledge, a change in attitudes towards stronger disapproval and an increased likelihood of taking assertive action when exposed to secondhand smoke in the family. The results of this study point to the fact that there is a need to give emphasis to passive smoking in the home environment and that the women's pregnancy is an effective conduit to increasing knowledge and bringing about change. The intervention model can become a part of the standard protocol for the care of pregnant women in hospital settings.