The study purpose was to test the effect of a school- and home-based alcohol, tobacco, and other drug (ATOD) prevention program on reducing environmental, parent, and child risk factors for ATOD use. The design was a three-group pretest-posttest with interviews at baseline and 1 and 6 months post-intervention. The sample was 126 parents and their 5- to 6-year-old children from three elementary schools serving high-risk children. The quality of the home environment, parents' depressive symptoms and school activity involvement, and parents' perception of child adjustment were measured. A school- and home-based version of Beginning Alcohol and Addictions Basic Education Studies (BABES) with a parent-child interaction component (BABES Plus) was compared to a classroom-only version of BABES (BABES Only) and a no-treatment control group. The quality of the home environment improved and depressive symptoms decreased over the post-intervention period for the BABES Plus group, but not for the other two groups. The BABES Only group had greater parent involvement in school activities at 6 months post-intervention, compared to the other groups. Children's anxiety/withdrawal decreased and social competence increased over time for all groups. The effect of the BABES Plus intervention was demonstrated at 6 months for environmental and parental risk factors.