Background: This study describes the levels and patterns of television (TV) viewing in Brazilian adults and investigates associations of TV viewing with hypertension, type 2 diabetes, and heart disease. Methods: Data from the Brazilian Health Survey, a nationally representative survey that was conducted in 2013 (N = 60,202 men and women aged ≥18 y), were used. Information regarding TV viewing, physician diagnoses of type 2 diabetes, hypertension, and heart disease was collected via interview-administered questionnaire. Data on covariables (including chronological age, educational status, skin color, sodium consumption, sugar consumption, tobacco smoking, alcohol consumption, and leisure-time physical activity) were also self-reported. Logistic regression models and population attributable fractions were used for the etiological analyses. Results: The prevalence (95% confidence interval) of >4 hours per day of TV viewing was 12.7% (12.0–13.4) in men and 17.5% (16.8–18.3) in women. Men and women being younger or older, moderately educated, living alone, smoking tobacco, and drinking alcohol were associated with higher reported TV viewing time. Odds ratios (95% confidence interval) revealed that >4 hours per day of TV viewing was associated with type 2 diabetes [male: 1.64 (1.23–2.17) and female: 1.33 (1.09–1.63)], hypertension [male: 1.36 (1.14–1.63) and female: 1.20 (1.05–1.37)], and heart disease [male: 1.96 (1.43–2.69) and female: 1.30 (1.00–1.68)]. Exceeding 4 hours per day of TV viewing was responsible for 6.8% of type 2 diabetes, 3.7% of hypertension, and 7.5% of heart disease cases. Conclusions: Independent of covariates, >4 hours per day of TV viewing was associated with type 2 diabetes, hypertension, and heart disease. High volumes of TV viewing are prevalent and appear to contribute to chronic disease burden.