The objective of this study was to identify excessive screen time, through the use of TV and other screen-based devices, including computers, videogames, tablets and smartphones, and analyze associated demographic, behavioral and anthropometric correlates. This is a cross-sectional school-based epidemiological study of approximately 17,000 schoolchildren aged 4-20 years who participated in the 2014 Healthy Paraná Project. Anthropometric measurements were collected by applying a questionnaire with structured questions. Excessive screen time was defined as the combined use of TV and other screen-based devices for > 2 hours/day. Data were analyzed using bivariate analysis and hierarchical multiple regression. e overall prevalence of excessive screen time was 70.4% [68.1–72.9]. Multivariate analysis showed a significant association between excessive screen time and age (OR = 1.92; 95%CI: 1.60–2.33), economic status (OR = 2.48; 95%CI: 1.99–3.17), mother’s schooling (OR = 1.98; 95%CI: 1.57–2.68), living area (OR = 1.26; 95%CI: 1.04–1.56) and urbanization (OR = 2.94; 95%CI: 2.41–3.75). Among the behavioral correlates, less physical activity (OR = 1.42; 95%CI: 1.25–1.85), low fruit/vegetable intake (OR = 2.89; 95%CI: 2.25–3.70), consuming sweetened products/soft drinks (OR = 2.07; 95%CI: 1.63–2.70) and fewer hours of sleep (OR = 2.01; 95%CI: 1.60–2.62) were independently associated with excessive screen time. Likewise, excess body weight (OR = 1.81; 95%CI: 1.35–2.51) and abdominal fat (OR = 2.01; 95%CI: 1.62–2.73) were significantly associated with the outcome. In conclusion, the findings of the study suggest that policies and interventions targeting health education programs in school and family settings should include elements that focus on reducing excessive screen time.