Beyond being a national measure of success, export diversification is closely linked to regional development, local employment, innovation capacity, and economic resilience. In the current study, we investigate the impact of export diversification on economic growth by provinces in the case of Türkiye for the period 2004-2018. For the purpose of the study, we employ static panel data models using Fixed Effects (FE) and Random Effects (RE) estimators, which account for unobserved heterogeneity. The findings of the study show that there is a significant negative relationship between per capita income and export intensity (HHI and GINI). In other words, as export diversification increases, per capita incomes increase. On the other hand, the coefficients obtained for the THEIL index are statistically insignificant. Therefore, it can be argued that indices measuring different dimensions of export diversification reflect different effects despite their conceptual similarities. The findings suggest that promoting export diversification can enhance regional economic growth and resilience, indicating that policymakers should prioritize strategies that encourage diversification of export portfolios, especially in underdeveloped regions, to foster balanced economic growth.