The purpose of this study was to examine the cumulative impact of parental nonstandard work schedules (NWS) on adolescent alcohol and cigarette use, with a focus on the mediating role of parent–child communication. Using the National Longitudinal Survey of Youth 1979 and its Child Supplement, our path analyses revealed that (a) parental NWS affected adolescent alcohol and cigarette use via the openness of parent–child communication rather than the frequency of parent–child communication and (b) the pattern and directionality of the mediating effects differed by who worked NWS, when parents worked NWS, and what types of NWS parents worked. Implications and directions for future studies are discussed.