Using a longitudinal, large-scale sample of British twins, we addressed the prediction of both cognitive abilities and behavioral adjustment from eight domains of environmental risk: minority status, socio-economic status, maternal medical factors, twin medical factors, maternal depression, chaos within the home environment, and parental feelings towards their children and discipline. Participants included 5765 families with twins (49.1% male) born in 1994 and 1995. Aspects of environmental risk were assessed from birth until the children's third birthdays; outcome measures were assessed at their fourth birthdays. Overall prediction of outcome (via multiple regression analysis) was moderate (R = 0.23 -0.48). SES and chaos were the strongest predictors for the cognitive outcomes whereas for total behavior problems the more proximal parenting factors were also dominant. Future analyses will investigate these environmental risk indicators in the context of the genetically sensitive twin design. (Contains 7 tables.)