Adolescents' perceptions of persons their age who smoke cigarettes (also known as prototypes of smoking peers) play a critical role in an adolescent's decision to start smoking. However, adolescents' perceptions of their peers who do not smoke (prototypes of nonsmoking peers) could be implicated in adolescents' smoking decisions as well. In the present study, the authors examined the additional role of nonsmoker prototypes in adolescents' smoking onset and regular smoking. At seven high schools, Dutch students (n = 1,035) between the ages of 12 and 15 years who were attending the eighth grade provided self-reported data on their smoker and nonsmoker prototypes and smoking behavior during a baseline and 6-month follow-up measurement. Logistic regression analyses showed that both smoker and nonsmoker prototypes assessed at Time 1 predicted smoking onset by Time 2 among nonsmoking adolescents. However, only nonsmoker prototypes predicted regular smoking among adolescents who smoked occasionally at baseline. (Contains 3 tables and 3 notes.)