Problem Statement: As the classical Iranian architecture went out of fashion during the Second Pahlavi Era, Iranian cities were poised for renovation. In the same period, the Soviet modernization campaign in Uzbekistan led to major developments in the country. In this light, International Style architecture emerging in the two countries appears to have some similarities and differences. Research Objective: This study aims to discover how the International Style was introduced, developed, and affected the architecture and construction practices in Iran and Uzbekistan to answer the following questions: Have modernist intellectual, political, and social movements in Iran and Uzbekistan influenced architecture and construction and the introduction of the modernist International Style in the two countries? What is the nature and structure of International Style architecture in Iran and Uzbekistan, and what are their similarities and differences? Research Method: The present work is a comparative study and adopts a qualitative approach based on documentary and field studies. Historical– theoretical foundations were gathered by the interpretive historical method, and architectural works were analyzed by a descriptive– analytical approach. The statistical population consists of International Style buildings constructed in Iran and Uzbekistan during the Second Pahlavi Era, and the sample comprises structures belonging to the same period (construction year) that share stylistic physical and functional similarities. Conclusion: The results are suggestive of the objective, functional, and physical manifestation of the modernistic International Style components in both countries, but objective components appear more accentuated. Uzbekistan, however, displayed an attempt to restore its historical roots from 1971 to 1983, which is reflected in the nationalistic style of architecture materialized in the Islamic decorations of the building faç ades dating back to this period.