This study investigated the effects of a family-centered intervention that involved parents in weekly assessments and daily routine activities for promoting young children's language and behavior. Forty-one 3-5-year-old children at-risk for language and behavior problems, recruited from three developmental preschools, were randomly assigned to a control and an intervention group that received parent-professional support. Analyses of covariance (ANCOVAs) were used to examine whether groups differed on post-test scores on the Test of Early Language Development-Third Edition and Eyberg Child Behavior Inventory, using pre-test scores as a covariate. Results showed that children in the intervention group outperformed children in the control group on both tests. The study indicated that family-centered intervention is an effective method for empowering parents to identify and implement concrete solutions to their children's problems, especially when done as part of a professional collaboration.