Contingency theorists have consistently identified size as a major factor influencing the structure of an organization. This study examines the size-structure relationship in a set of voluntary sport organizations (VSOs). The results of the study generally support the trends identified in the organization theory literature; they also demonstrate that VSOs have unique features that influence the effect that size has on their structural arrangements. This is most noticeable when the association, or more specifically the lack of association, between size and the structure of decision making is examined. The relationship between professionals and volunteers, and their associated struggle for control of these organizations, is identified as a principal factor contributing to this situation.