The aim of the article is the analysis the role of regional parties in shaping Indian foreign policy at the turn of the 20th and 21st centuries, which requires examining the premises for increasing the activity of regional parties in the international sphere and identifying formal and informal instruments by means of which they influence the process of creating foreign policy. The theoretical tool used to analyze the activity of regional parties in India constitutes the liberal theory of foreign policy is. Its use will allow us to verify the accepted hypothesis that regional parties are dynamizing India’s foreign policy, contributing to the enrichment of its content and objectives, especially with regard to relations with neighboring countries and cooperation in the region of South Asia. The first part of the article discusses the main assumptions of the liberal theory of foreign policy. The second part identifies conditions and institutional, as well as legal frameworks that condition international activity of regional parties. The third part presents the evolution of the Indian party system and characterizes the selected regional parties. The fourth part analyzes the increase of the activity of international regional parties on the example of some regional parties selected based on their importance and power of their influence. The summary presents the usefulness of the liberal theory of foreign policy in the study on the increase of the importance of regional parties in shaping India’s foreign policy