This study analyses Indonesia’s economic diplomacy strategy in developing export markets through its participation in the Sirha Budapest international trade exhibition. The research is motivated by Indonesia’s efforts to diversify export destinations beyond traditional markets by strengthening its presence in Central and Eastern Europe. It aims to examine how the Indonesian Embassy in Budapest and the Indonesia Trade Promotion Centre (ITPC) Budapest utilize Sirha Budapest as an instrument of trade promotion and economic diplomacy. This study employs a qualitative descriptive-analytical approach. The data were obtained through in-depth interviews with the minister counsellor for economic affairs at the Indonesian Embassy in Budapest and the head of ITPC Budapest, complemented by official government documents, trade reports, and relevant literature. The findings suggest that Sirha Budapest serves as strategic platform for promoting Indonesian products, facilitating business matching, and creating opportunities for trade cooperation with partners in Central and Eastern Europe. However, the effectiveness of these efforts depends on sustained post-event follow-up, exporters’ compliance with European Union market standards, and the diversification of export products. From the perspective of Neoliberal Institutionalism, the study argues that international trade exhibitions function as informal institutional arenas that facilitate repeated interactions, reduce uncertainty among economic actors, and strengthen institutional cooperation in support of Indonesia’s economic diplomacy.