The workshop has been held since 2001 in conjunction with major computational linguistics conferences (ACL, COLING, LREC, EACL). It attracts the attention of an ever-growing community working on a variety of languages and linguistic phenomena and represents an important venue for the community to interact, share resources and tools, and collaborate on efforts for advancing the computational treatment of multiword expressions.In this 13th edition of the workshop, we have called for papers on major challenges in MWE processing, both from theoretical and computational viewpoints, focusing on research related (but not limited) to the following topics:• Manually and automatically constructed lexical resources • MWE representation in lexical resources • MWE annotation in corpora and treebanks • MWEs in non-standard language (e.g. tweets, forums, spontaneous speech) • Original MWE discovery methods (e.g. using word embeddings, parallel corpora)• Original MWE in-context identification methods (e.g. using deep learning, topic models) • MWE processing in syntactic frameworks (e.g. HPSG, LFG, TAG, universal dependencies) • MWE processing in semantic frameworks (e.g. WSD, semantic parsing)• MWE processing in end-user applications (e.g. summarization, machine translation) • Orchestration of MWE processing with respect to applications • Evaluation of MWE processing techniques • Models of first and second language acquisition of MWEs • Theoretical and psycholinguistic studies on MWEs • Crosslinguistic studies on MWEs Submissions included both long and short papers. In total, 34 papers (22 short and 12 long) were submitted to the main track of the workshop. From those, 7 papers (4 short and 3 long) were accepted as oral presentations and 14 papers (11 short and 3 long) were accepted as posters. The overall acceptance rate is 62% including oral presentations and posters, short and long papers.Additionally, 6 system description papers and 1 shared task description paper were submitted to the shared task track. The former were all selected as posters and the latter as an oral presentation. The reviewing modalities were different in this track, therefore we do not count these papers in the workshop acceptance rate.In addition to the oral and poster sessions, the workshop featured an invited talk by Paul Cook, from the University of New Brunswick, Canada. The presentation was entitled Exploiting multilingual lexical 1 http://multiword.sf.net/mwe2017 2 http://www.siglex.org/ 3 http://parseme.eu/ iii resources to predict the compositionality of MWEs. The program also included a panel discussion on the future directions of the MWE community and the SIGLEX Section.We would like to thank the members of the program committee for the timely reviews, authors for their valuable contributions, shared task organizers, annotators, and system developers for their hard work, and all involved participants for their interest in the workshop. We also want to thank the IC1207 COST Action PARSEME and SIGLEX for their endorsement and support, as well a...