Pacific Island countries face a range of development challenges, including smallness, distance from major markets and capacity constraints. Regional service delivery, or pooling, has been advocated as a means of addressing these challenges. This article presents the findings from the first comprehensive study of pooling initiatives in the Pacific. It draws on a review of the literature pertaining to 20 pooling initiatives identified in the region and on interviews with stakeholders involved in many of those initiatives. The study finds that experience with pooling among Pacific Island countries has not met the optimistic expectations of advocates, including development partners. This is the result of the challenges inherent in voluntary regionalism, which are exacerbated by the diversity of Pacific Island states and political economy constraints. The article concludes that an incremental approach to expansion of regional service provision in the Pacific is both likely and appropriate given these factors.