This paper investigates the syntax of prefix concord and offers a principled explanation of various syntactic restrictions on prefix concord constructions in Saaroa. First, I argue for a structural constraint on the prefix concord effect: this effect can only occur within the vP-level projection. Second, I show that prefix concord constructions display the core properties of restructuring constructions (e.g., long NP movement and clitic climbing), but I also argue against a serial verb construction analysis, in contrast to Tsuchida (2000) and Adelaar (2004). Third, I propose that the concord effect is a reflex of Multiple Agreement (cf. Hiraiwa 2001, 2005; Chomsky 2004): under the Multiple Agree framework, I propose that the prefix concord effect is the morphological realization of multiple checking/valuation of a formal feature and that the intervening effect on prefix concord constructions results from the feature-spreading conflict. Finally, I argue that various restrictions on Saaroa prefix concord constructions are deducible from attested universal conditions, namely the phase impenetrability condition and the feature activity condition.