The aim of this study is to examine Türkiye’s competitive strength in the foreign trade of sunflower seeds and the long-term transformation of its export markets. The study utilised foreign trade data for sunflower seeds (HS code 120600) for the period 2010–2025. Türkiye’s foreign trade performance was assessed using indicators such as exports, imports, the trade balance, the export-to-import coverage ratio and unit value. The Revealed Comparative Advantage (RCA) and Symmetric Revealed Comparative Advantage (RSCA) indices were utilised to determine international competitiveness. The concentration and diversification structure of export markets was analysed using the Herfindahl-Hirschman Index (HHI), the concentration ratio of the top four countries (CR4) and the number of partner countries. The long-term transformation of markets was analysed by comparing country shares during the 2010–2012 and 2023–2025 periods. The findings indicate that Türkiye possessed a revealed comparative advantage in sunflower seed exports throughout the entire period under review. The RCA value stood at 3.07 in 2010 and reached 5.83 in 2025. RSCA values followed a positive trend throughout all analysis periods. In contrast, Türkiye consistently recorded a trade deficit in sunflower seed trade, except in 2024. Analyses of the structure of export markets revealed that the HHI fell from 0.229 to 0.098, the CR4 declined from 70.06 per cent to 50.27 per cent, and the number of export partners rose from 49 to 93, indicating a significant expansion of the market. Country-by-country comparisons revealed that the weight of traditional markets has shifted and new export markets have gained importance. The findings of this study indicate that Türkiye’s growing export capacity and comparative advantage in the sunflower seed trade coexist with a dependence on imports and a trade deficit; however, export markets have evolved into a geographically more diversified structure.