A randomized controlled trial was used to evaluate a parent training intervention for caregivers with preschool-age children with developmental disabilities. The 21 families in the experimental group received usual care plus the 12-week Incredible Years Parent Training Program with developmental delay modifications. Families in the control group (n = 23) received usual care, including early childhood education and related services. Results suggest that this parent training intervention was superior to usual care for young children with developmental delays or disabilities in reducing negative parent–child interactions and child behavior problems. Participants in the experimental group indicated high satisfaction with treatment. Additional research is necessary to document maintenance and generalization of treatment outcomes.