This book constitutes the refereed proceedings of the 38th Annual German Conference on Artificial Intelligence, KI 2015, held in Dresden, Germany, in September 2015. The 15 revised full technical papers presented together with 14 technical communications, 4 doctoral consortium contributions, and 3 keynotes were carefully reviewed and selected from 58 submissions. The conference provides the opportunity to present a wider range of results and ideas that are of interest to the KI audience, including reports about recent own publications, position papers, and previews of ongoing work.