This book constitutes the refereed proceedings of the 13th International Baltic Conference on Databases and Information Systems, DB&IS 2018, held in Trakai, Lithuania, in July 2018. The 24 revised papers presented were carefully reviewed and selected from 69 submissions. The papers are centered around topics like information systems engineering, enterprise information systems, business process management, knowledge representation, ontology engineering, systems security, information systems applications, database systems, machine learning, big data analysis, big data processing, cognitive computing.