This Workshop familiarizes participants with the Circle of Security Parent Course (COS) as an effective, evidence-based intervention model for children with disruptive behaviors, including affective and temper dysregulation. This user-friendly model for intervention meets the growing demand for a conceptual and practical framework for understanding children’s acting-out, externalizing problems, along with an appreciation for children’s biological vulnerability as it interacts with parent care-giving capacities. Through extensive videotape review, participants learn to identify common behavioral patterns in children with temper and affective dysregulation, become familiar with the practical application of this model, and learn to effectively apply the COS model to strengthen parents’ ability to observe and improve their care-giving capacity.