Objective: The purpose of this study was to examine how lifestyle behaviors in the context of physical activity levels and screen time are associated with school absenteeism.

Methods: We analyzed 2005–2008 NHANES data of proxy interviews for 1048 children aged 6–11 years and in-person self-reports of 1117 adolescents aged 12–18 years. Missing 10% of school days during the past school year was defined as severe school absenteeism (SSA).

Results: Watching TV ≥2 hours a day was significantly associated with SSA among both children (OR = 3.51 [1.03–12.0]) and adolescents (OR = 3.96 [1.84–8.52]) compared with their peers watching(OR = 12.4 [1.43–108]) and highly active children (14.8 [2.82–77.7]) had higher odds of SSA compared with children with medium levels of physical activity. No associations were observed for either children 0.57 ([0.16–1.99]) or adolescents (0.94 [0.44–2.03]) using a computer ≥3 hours a day.

Limitations: Cross-sectional study involving self-reports. Transportation to and from school not included in physical activity assessment. Absenteeism was not validated with report cards. Unable to account for the absence type or frequency of illness or injury. No psychometric properties provided for subjective measures regarding participants’ attitudes and characteristic traits towards physical activity, TV viewing, and school attendance.

Conclusions: Excessive TV watching among children and adolescents, and inactivity and high activity levels (≥7 times per week) among children are independently associated with severe school absenteeism.