Background: This evaluative study assesses the efficacy of a school-based secondary prevention program consisting of creative expression workshops for immigrant and refugee preschoolers in a predominantly South Asian multiethnic neighborhood. Coincidentally, the program began in the wake of the tsunami. Method: Pretest and posttest data were collected from the parents and teachers of 105 preschoolers in 10 classes randomly assigned to an experimental or control status. The parents' and teachers' versions of the Strengths and Difficulties Questionnaire were used to assess the children's mental health. The family's ethnic origins and premigration experiences of organized violence were considered in the analysis. Results: According to both the teachers' and parents' reports, the children in the experimental group benefited moderately from the program, which appeared to reduce the SDQ global score of children whose families had experienced violence in their homelands (t(21) = 3.83, p = 0.001 (MT[subscript 1] = 12.81, MT[subscript 2] = 9.59)), in particular those from South Asia. Conclusion: This study provides some evidence that immigrant preschoolers whose families have experienced adversity before migration can benefit from the creative expression workshops. Further studies are needed to determine if this program can help address the effects of mass media exposure to a disaster or traumatic event on vulnerable communities.