This book constitutes the refereed proceedings of the 11th Pacific Asia Workshop on Intelligence and Security Informatics, PAISI 2016, held in Auckland, New Zealand, in April 2016 in conjunction with PAKDD 2016, the 20th Pacific-Asia Conference on Knowledge Discovery and Data Mining. The 7 revised full papers presented together with 7 short papers were carefully reviewed and selected from 23 submissions. The papers cover network-based data analytics, data and text mining, and cyber security and infrastructure protection.