AbstractBackgroundChildren in households of lower socioeconomic status (SES) are more likely to be overweight/obese. We aimed to determine if home physical activity (PA) environments differed by SES and to explore home environment mediators of the relation of family SES to children’s PA and sedentary behavior.MethodsParticipants were 715 children aged 6 to 11 from the Neighborhood Impact on Kids (NIK) Study. Household SES was examined using highest educational attainment and income. Home environment was measured by parent report on a survey. Outcomes were child’s accelerometer-measured PA and parent-reported screen time. Mediation analyses were conducted for home environment factors that varied by SES.ResultsChildren from lower income households had greater media access in their bedrooms (TV 52% vs. 14%, DVD player 39% vs. 14%, video games 21% vs. 9%) but lower access to portable play equipment (bikes 85% vs. 98%, jump ropes 69% vs. 83%) compared to higher income children. Lower SES families had more restrictive rules about PA (2.5 vs. 2.0). Across SES, children watched TV/DVDs with parents/siblings more often than they engaged in PA with them. Parents of lower SES watched TV/DVDs with their children more often (3.1 vs. 2.5 days/week). Neither total daily and home-based MVPA nor sedentary time differed by SES. Children’s daily screen time varied from 1.7 hours/day in high SES to 2.4 in low SES families. Media in the bedroom was related to screen time, and screen time with parents was a mediator of the SES--screen time relationship.ConclusionsLower SES home environments provided more opportunities for sedentary behavior and fewer for PA. Removing electronic media from children’s bedrooms has the potential to reduce disparities in chronic disease risk.