In this chapter we will review changing knowledge of the impact of cigarette smoking on women’s health, smoking patterns among women, special factors influencing smoking among women, and the application of this knowledge to more effective approaches to help women quit smoking. Our discussion of health impact and smoking patterns reflect what now seems a simple and easily understood phenomenon: smoking has increased among women in the past several decades and the health impact of this in-creased exposure is now being seen in women’s rates of smoking-related diseases.