Smoking behavior is a threat for Indonesian teenagers, including in the city of Jayapura, Papua province. The purpose of this study was to access Jayapura teenagers smoking behavior and knowledge including parents and other family members. The study was conducted on 78 respondents (grade 7, aged 11-14 years old), using cluster random sampling for selecting the public and private junior high school in Jayapura. The data collected was smoking behavior of respondents, parents and other family members (using self-reported questionnaire), and respondents' knowledge about the dangers of smoking (using tests with Cronbach's alpha 0.701). Data were analyzed descriptively and analytically using Chi-square, 95 % level of significant. The results showed 29.3 % of teenagers, 69.23 % of parents and 25.6 % of other family members were smokers, their knowledge was low (an average score of 60.81 out of 100), there was no significant statistical relationship between knowledge and smoking behavior among respondents (p = 0.079), and there is no significant relationship between teenagers behavior with the behavior of the parents (p = 0.609) and other family members (p = 0.578), 87 % of teenagers became smokers because there were individuals who smoke at home.
Keywords: Knowledge; Smoking behavior; Teenagers.