More than half of young adolescents, 13 to 15 years old, suffer exposure to secondhand smoke (SHS) at home and in public places. Despite threats to adolescent health and well-being, little research has been done to identify factors that enable adolescents to avoid SHS. The objective of this study was to develop a model to predict SHS avoidance behavior among young adolescents. The impact of gender differences on predictor variances was investigated. Model testing was conducted using structural equation modeling on data from 1,291 nonsmoking Taiwanese middle school students. Attitude toward SHS is an important factor influencing the avoidance behavior of adolescents. The explanatory model of SHS avoidance behaviors provides useful information for program development aimed at decreasing adolescent exposure to SHS. Interventions focused on influencing adolescent attitudes toward SHS and supporting avoidance self-efficacy are needed.