Mainstream primary and elementary schools are increasingly involved in delivering small group social skill interventions for pupils with special needs, particularly in the light of the evidence indicating the impact of social skill competency on later life outcomes. Despite significant investment by schools in training and resources to implement these interventions, very little is currently understood about the characteristics of effective small group social skill interventions for the five to eleven age phase. The purpose of the current review was to provide a preliminary overview of the characteristics of such interventions. Searches of four key databases were conducted between September 2017 and January 2018. Eleven studies met criteria for inclusion. The review found that the area is at an early stage of development with a lack of clarity in conceptualising, measuring and judging effectiveness of small group social skill interventions for the primary age phase. Implications for future evaluative research methods are discussed, including a need for collaboration between schools and researchers to develop iterative, implementation-based evaluative studies of small group social skill interventions.