This action research project implemented an intervention program to increase prosocial skills among 3- to 5-year-olds in at-risk prekindergarten classrooms. Participating were 65 students from 2 prekindergarten classrooms in 2 schools. Evidence of problems in social skills was gathered through anecdotal records and observational checklists completed for 39 students. Analysis of probable cause data revealed that students demonstrated a lack of emotional intelligence that inhibited the development of social competence. Area early childhood professionals reported that students exhibited an inability to handle conflict, a lack of cooperation, poor relationships, and an inability to use expressive language in emotional situations. The intervention was comprised of cooperative learning activities, training in emotional intelligence, incorporation of multiple intelligence lessons, implementation of Second Step Social Skills and Violence Prevention Program lessons, and inclusion of an anti-bias curriculum. Post-intervention data indicated that the targeted prekindergarten students demonstrated an increase in prosocial behavior and emotional intelligence and that learned social skills transferred across the curriculum. (Nine appendices include data collection instruments and sample materials. Contains 32 references.) (Author/KB)