To advance his reform agenda, particularly in peripheral regions, Mohammad Mossaddeq supported the establishment of political parties. The National Saādat Party of Iran was one such organization, established in Kurdistan and Kermanshah. Kurdistan had limited urban development, with more than four-fifths of its population living in rural areas under a landlord-peasant system (nezām-e arbāb-raʿiyyati). Drawing on archival and library sources and employing a descriptive-analytical approach, this study examines the party's formation, political and social functions, consequences, and local responses to its activities. The findings show that the Saādat Party was a state-established organization dependent on central government support and intended to advance Mossaddeq's policies, particularly the Seventeenth National Consultative Assembly elections and the law on "Increasing the Share of Peasants." Although it temporarily mobilized segments of the urban middle class and peasantry, its lack of durable social roots and confrontation with powerful landlords and influential clerics intensified political conflict and instability in Kurdistan. The party also failed to establish a durable alliance with local social forces or to overcome the resistance of entrenched traditional elites. Consequently, Mossaddeq's reform objectives were not fully realized in the region. Following the downfall of Mossaddeq's government and the loss of central political support, the Saādat Party rapidly weakened and was eventually dissolved. Its experience demonstrates that state-led reform initiatives, when dependent on central authority and lacking durable institutions, broad social coalitions, and effective engagement with local power structures, remain vulnerable to resistance and political instability in peripheral regions and are difficult to sustain over time.