Every year, more than 400,000 Americans die prematurely because of tobacco use, and most users began smoking during their teen years. Adolescent tobacco use remains the nation's most preventable threat to life and health. A better understanding of the relationships between susceptibility to smoking and intention to smoke on smoking behavior by ethnicity, age, and gender is useful for program planners and health educators in designing ethnic, age, and gender specific strategies for tobacco control and prevention initiatives. The purpose of this study was to test the relationships between susceptibility to smoking and intention to smoke on smoking behavior among adolescents by ethnicity, age, and gender. The theory of reasoned action by Ajzen and Fishbein formed the basis of this study and supports the findings and conclusions. To get good representation of the study populations, the study utilized secondary data from the 2007 National Survey on Drug Use and Health. The study population includes person ages 12-17 years old, smokers and nonsmokers, who represent White, African American, Hispanic, Asian, Multi-Racial, American Indian, and Native Hawaiian race/ethnicities. Data were analyzed with Kruskal-Wallis test, analysis of variance (ANOVA), multiple regression analysis, and bivariate Spearman correlation. A statistically significant positive relationship was found between participants’ susceptibility to smoking and their intentions to smoke (r = .57, p < .01). More specifically, a significant difference was found among ethnic groups on smoking intentions and among age groups on susceptibility to smoking. Positive social change can occur through improved efforts geared toward primary, secondary, and tertiary interventions. This can result in empowerment programs and enhanced decision making, useful for adolescents of different ethnic groups to resist social and environmental pressures.