ABSTRACT
This study examined the relationship between economic complexity and institutional quality indicators in the member states of the Organization of Islamic Cooperation. A balanced panel dataset covering the period 2002-2023 was constructed using the Economic Complexity Index and the indicators of Rule of Law, Control of Corruption, and Efficiency of Public Administration. The analysis employed the Panel Fourier Toda-Yamamoto causality approach, which allowed structural breaks and institutional fluctuations to be considered within the panel framework. The findings indicated a statistically significant one-way causality running from economic complexity to Rule of Law and Control of Corruption. However, no statistically significant causality was identified from institutional quality indicators to economic complexity in the short term. These results suggest that, in Organization of Islamic Cooperation countries, the development of economic structures plays an important role in shaping institutional mechanisms.