OBJECTIVE: This study examines the development of active television (TV) watching behaviors across the first 2 years of life in a racially and ethnically diverse, low-income cohort and identifies caregiver and child predictors of early TV watching. METHODS: We used longitudinal data from infants enrolled in the active control group (N = 235; 39% Latino; 29% Black; 15% White) of Greenlight, a cluster randomized multisite trial to prevent childhood obesity. At preventive health visits from 2 months to 2 years, caregivers were asked: "How much time does [child's first name] spend watching television each day?" Proportional odds models and linear regression analyses were used to assess associations among TV introduction age, active TV watching amount at 2 years, and sociodemographic factors. RESULTS: Sixty-eight percent of children watched TV by 6 months, and 88% by 2 years. Age of TV introduction predicted amount of daily active TV watching at 2 years, with a mean time of 93 minutes if starting at 2 months; 64 minutes if starting at 4 or 6 months; and 42 minutes if starting after 6 months. Factors predicting earlier introduction included lower income, fewer children in household, care away from home, male sex, and non-Latino ethnicity of child. CONCLUSIONS: Many caregivers report that their infants actively watch TV in the first 6 months of life. Earlier TV watching is related to sociodemographic factors yet predicts more daily TV watching at 2 years even controlling those factors. Interventions to limit early TV watching should be initiated in infancy.