Using a large contemporary data set (the National Longitudinal Survey of Youth-Child Supplement), the authors examined the effects of parental work schedules on adolescent risky behaviors at age 13 or 14 and the mechanisms that might explain them. Structural equation modeling suggests mothers who worked more often at night spent significantly less time with children and had lower quality home environments, and these mediators were significantly linked to adolescent risky behaviors. Similar effects were not found for evening work schedules, while other types of maternal and paternal nonstandard work schedules were linked to higher parental knowledge of children's whereabouts, which led to lower levels of adolescent risky behaviors. Subgroup analyses revealed that boys, those in families with low incomes, and those whose mothers never worked at professional jobs may particularly be affected by mothers working at nights, due to spending less time together, having a lower degree of maternal closeness, and experiencing lower quality home environments. In addition, the effects of maternal night shifts were particularly pronounced if children were in the preschool or middle-childhood years when their mothers worked those schedules. Implications and avenues for future research are discussed. (Contains 5 tables and 3 figures.)