Early intervention is valuable in preventing negative behavioural outcomes and promoting positive social competence in young children with externalizing behaviours. Interventions that teach social problem solving (SPS) are a promising solution, as children with behavioural difficulties often have deficits in these skills. School-based SPS programming has been shown to prevent and remediate externalizing behaviours for older children, but a summary of its effectiveness for preschoolers in early childhood settings is unavailable. The purpose of the current meta-analytic review was to (a) provide a summary of the characteristics of current SPS instruction in preschool settings and (b) examine the effectiveness of interventions that include an SPS component in decreasing externalizing behaviours and increasing social competence among preschoolers. Using meta-analytic review, we present common characteristics of preschool interventions that include SPS and provide evidence for the efficacy of these interventions in reducing externalizing behaviours and increasing social competence in preschoolers.