This book constitutes the refereed proceedings of the 4th EAI International Conference on Blockchain Technology and Emerging Applications, BlockTEA 2025, held in Venice, Italy, during September 18–19, 2025.The 12 full papers and 2 short papers presented in this volume were carefully reviewed and selected from 45 submissions. They are organized in the following topical sections: Blockchain and AI; Protocol and Security; Short papers; Applications; and Smart Contract Verification.