Objective. To examine associations between social ecological factors and Dutch adolescents' TV viewing. Design. Cross-sectional examination of predictors of adolescents' TV viewing. Participants. A total of 338 adolescents, aged 14 years (55% boys). Measurements. Adolescents self-reported their age, ethnicity and TV viewing (dichotomized at two hours/day) and responded to items from all three social ecological domains; individual (cognitions based on the Theory of Planned Behaviour and TV viewing habit strength, and other behaviours, such as computer use), social (parental rules about TV viewing and parental TV viewing behavior) and physical environmental factors (TV in bedroom, physical activity equipment available). Parents reported demographic factors (e.g., ethnicity, education level), and their own TV viewing (mins/day); adolescents' weight status (not overweight vs. overweight/obese) was calculated from objective measures of height and weight. Logistic regression analyses examined associations between socio-ecological factors and adolescents' TV viewing, and whether associations were moderated by adolescents' sex, parents' education and ethnicity. Results. Compared with others, overweight/obese adolescents (odds ratio (OR)=3.0; p < 0.001), those with high computer use (OR=2.3; p < 0.0001), with high TV viewing habit strength (OR=1.3; p < 0.0001), and those whose parents had high levels of TV viewing (OR=2.4; p < 0.01) were more likely to exceed two hours of TV viewing per day. The association with habit strength was moderated by gender, and the association with parents' TV viewing was moderated by parents' education and ethnicity. Conclusions. Interventions should target parents' TV viewing behaviors and aim to amend habitual, 'mindless' TV viewing among adolescents.