In a previous study, Serna, Nielsen, Lambros, and Forness (2000) demonstrated that a 12-week universal intervention in three Head Start classrooms significantly improved outcomes on 5 of 10 measures of symptoms or impairment in mental health, compared to outcomes for children in two control classrooms. Children meeting clinical cutoffs for mental health risk also maintained or improved their performance as a result of such primary prevention compared to control children at risk (Serna, Lambros, Nielsen, & Forness, 2002). The present study replicated the original, except the universal intervention was not conducted by a university preschool teacher but by regular Head Start teachers. Outcomes were significant on only two of eight outcome measures. The authors discuss them in terms of efficacy versus effectiveness.