This book constitutes the refereed proceedings of the 4th International Congress on Blockchain and Applications 2022, BLOCKCHAIN'22, held in L'Aquila, Italy, in July 2022. Among the scientific community, blockchain and artificial intelligence are a promising combination that will transform the production and manufacturing industry, media, finance, insurance, e-government, etc. Nevertheless, there is no consensus with schemes or best practices that would specify how blockchain and artificial intelligence should be used together. The 37 full papers presented in the main track were carefully reviewed and selected from more than 75 submissions. They contain the latest advances on blockchain and artificial intelligence and on their application domains, exploring innovative ideas, guidelines, theories, models, technologies, and tools and identifying critical issues and challenges that researchers and practitioners must deal with in the future research. The book also includes 3 papers from the WEB3-TRUST workshop and 2 papers from the Doctoral Consortium.