This paper studies the role of information on the evolution of beliefs and smoking in the United States in the 20th and early 21st centuries. We develop a dynamic and dynastic model of smoking, mortality and beliefs. The information about the harmfulness of smoking comes from three different sources: (i) learning from individual health shocks, (ii) medical information or public health messages and (iii) social learning, understood as the diffusion of information and beliefs within and across social groups over time. We estimate the model using data on smoking behavior, health information and data  on beliefs on the effect of smoking on health that cover several decades and different social groups that we assemble. The estimated model allows us to understand the role of each of these mechanisms and how they shaped smoking over the last century. We use the model to evaluate the long term effects of medical information across socioeconomic groups and time.