The two-volume set LNCS 11233 and LNCS 11234 constitutes the proceedings of the 19th International Conference on Web Information Systems Engineering, WISE 2018, held in Dubai, United Arab Emirates, in November 2018. The 48 full papers and 21 short papers presented were carefully reviewed and selected from 209 submissions. The papers are organized in topical sections on blockchain, security, social network and security, social network, microblog data analysis, graph data, information extraction, text mining, recommender systems, medical data analysis, Web services and cloud computing, data stream and distributed computing, data mining techniques, entity linkage and semantics, Web applications, and data mining applications.