This book constitutes the revised selected papers of the 12th International Workshop on Information Search, Integration and Personalization, ISIP 2018, held in Fukuoka, Japan, in May 2018. The volume presents 1 invited paper as well as 7 revised full papers, which were carefully reviewed and selected from 13 papers submitted to these post-conference proceedings. The papers are organized in topical sections on data integration; text and document management; advanced data mining techniques.