This book constitutes the proceedings of the 13th German Conference on Multiagent System Technologies, MATES 2015, held in Cottbus, Germany, in September 2015.The 11 full papers papers presented together with 2 short papers, 1 invited paper and 4 extended abstracts of doctoral papers in this volume were carefully reviewed and selected from 27 submissions. The papers are organized in topical sections on MAS engineering, modeling, and simulation; smart things working together; and innovative and emerging applications of MAS.