Passivization and non-active voice in Iranian languages are so challenging that it has led some researchers to deny the existence of passive voice in Farsi as the most studied modern Iranian language. In this study, various Kurdish, Bakhtiari, and Farsi data confirm the existence of non-active voices, including passive structures, in the family of Iranian languages. This paper examines the derivation of synthetic and analytic non-active constructions in these neighboring Iranian languages. Studying various non-active structures in the light of Alexiadou and Doron (2012. The syntactic construction of two non-active voices: Passive and middle. Journal of Linguistics 48. 1–34), as well as the constructivist approach (Alexiadou, Artemis, Elena Anagnostopoulou & Florian Schäfer. 2015. External arguments in transitivity alternations: A layering approach . Oxford: Oxford University Press; Hale, Kenneth L. & Samuel Jay Keyser. 1993. On argument structure and the lexical expression of syntactic relations. In Ken Hale & Samuel Keyser (eds.), The view from building 20: Essays in linguistics in honor of Sylvain Bromberger , 53–109. Cambridge: MIT Press; Marantz, Alec. 2013. Verbal argument structure: Events and participants. Lingua 130. 152–168 and others), we argue that it is plausible to account for these seemingly different structures uniformly. In our view, synthetic and analytical non-active voices share the same underlying structure and derivation, and their morpho-syntactic differences results from the combination of roots with different heads. To account for the observed diversity in non-active formation, the paper adopts the Concatenation Rule (Embick, David. 2015. The morpheme: A theoretical introduction . Berlin, München, Boston: De Gruyter Mouton: 178) and labels it as the Affixation Rule. To comply with the Affixation Rule, there can be no phasic head between the roots and non-active heads. Accordingly, the synthetic non-active voices result from the locality of [+ v ] roots and non-active heads. In the formation of analytic non-active voices, on the other hand, n or a heads act as blocking phase heads and prevent the affixation of the non-active heads with the roots.