This study examines the strategic factors influencing port usage in Thailand's logistics system, responding to the critical need for enhanced port competitiveness in Southeast Asia's rapidly evolving trade environment. Quantitative research was used to collect data from 378 relevant stakeholders, including shipping lines, freight forwarders, exporters, importers, and port authorities, through questionnaires. Multiple regression analyses identified and evaluated the key strategic factors influencing port usage. The research reveals significant differences in the strategic positioning of Bangkok Port (BP) and Laem Chabang Port (LCP), highlighting the unique roles each plays in Thailand's logistics network. Findings indicate that location, capacity, efficiency, and connectivity are primary factors affecting port choice among logistics operators. While these findings are specific to Thailand's port system, they offer valuable insights for other developing economies with similar dual-port systems, particularly those balancing established river ports with newer deep-sea facilities. This study contributes to the understanding of port competitiveness in Thailand and offers insights for policymakers and port authorities to enhance the strategic value of these critical logistics hubs. The research underscores the need for targeted investments and policy interventions to optimize the complementary roles of Bangkok Port and Laem Chabang Port in supporting Thailand's economic growth and trade competitiveness.