The use of tobacco remains a significant public health concern among Asian American (AA) adolescents. Understanding the factors that affect smoking progression among Chinese and Vietnamese adolescents in particular, may help in illuminating potential interventions that can be implemented to maximize scarce programming and resources. This study is a longitudinal cohort study with data collected in California via telephone over a two-year period. 1,270 Chinese and Vietnamese American adolescents were recruited via telephone listings from one southern and four northern California counties. Main outcomes were smoking susceptibility and change in smoking status. Examination of these adolescents indicated that in both groups: boys were more likely than girls to become susceptible to smoking, risk behaviors were associated with becoming smokers, having been susceptible at baseline was associated with susceptibility and smoking at follow-up, and the influence of friends was a predictor of susceptibility and smoking.