In consensually non-monogamous (CNM) relationships there is an open agreement such that one or both individuals involved in a romantic relationship may also have other sexual and romantic partners (Conley, Moors, Matsick, & Ziegler, 2013; Conley, Ziegler, Moors, Matsick, & Valentine, 2013). Research on CNM relationships has grown recently but is just beginning to understand how relationships among partners in CNM relationships may vary. The current research examines one type of CNM relationship, specifically polyamory, and uses a convenience sample of 3,530 self-identified polyamorous individuals who provided answers on various indices of relationship evaluation (e.g., acceptance, secrecy, investment size, satisfaction level, commitment level, communication, and sexual frequency). Measures were compared between two concurrent partners within each polyamorous relationship (i.e., primary and secondary partners). Participants reported less stigma as well as more investment, satisfaction, and commitment in their primary compared to secondary relationships, but reported more secrecy and greater quality of alternatives in secondary compared to primary relationships. We discuss how these results inform our understanding of the unique costs and rewards of primary secondary relationships in polyamory and suggest future directions based on these findings. To learn more about this project, see: https://osf.io/vs574/