Purpose of study: The aim of this pilot study was to examine a mind-body-based preventive intervention program and to determine relationships between children’s behavioral inhibition system (BIS) and behavioral activation system, stress, and stress reduction after the program. Design of study: Children participated in the program (n = 30) or in a control condition (n = 24). They filled out questionnaires before and after the program and reported their levels of stress before and after each of the five sessions. Method: The program consisted of weekly sessions. Each session incorporated yoga postures, visualization, and social exercises. Breathing techniques were integrated. Findings: Stress reductions were only seen in the intervention group and mainly in children with high BIS—irrespective of their behavioral activation system. Conclusion: The results demonstrate that children with high BIS may benefit from a mind-body-based stress reduction program.