This study employed the PRECEDE model to investigate the correlates of behavior to avoid environmental tobacco smoke (ETS) in adolescents. A total of 208 adolescents who were non-smoking and aged between 15 and 19 years old enrolled in junior programs in technical colleges in southern Taiwan were selected as participants. An anonymous questionnaire including demographic data, ETS avoidance scale, knowledge of ETS scale, attitude toward avoiding ETS scale, self-efficacy of avoiding ETS scale, perceptions of health resources for avoiding ETS in school scale, perceptions of ETS avoidance in families, perceptions of ETS avoidance in peers scale, whether the family smoke, and whether close friends smoke were used to collect data. The results showed: (1) behavior to avoid ETS for female adolescents was better than that of male adolescents; (2) attitude toward avoiding ETS, self-efficacy of avoiding ETS, perception of ETS avoidance in families, and perception of ETS avoidance in peers were significantly positive related to behaviors of avoiding ETS; (3) adolescents with close friends not smoking had a better behavior to avoid ETS; and (4) hierarchical regression analysis shows that gender, attitude toward avoiding ETS, perception of ETS avoidance in peers, and perceptions of ETS avoidance in families were the significant predictors, and could explain 54.5% of the total variance in behaviors to avoid ETS. Results of this study can serve as a reference on improving ETS avoidance among adolescents.