This volume constitutes the refereed proceedings of the Second International Conference on Computational Intelligence, Security and Internet of Things, ICCISIoT 2019, held in Agartala, India, in December 2019. The 31 full papers and 6 short papers were carefully reviewed and selected from 153 submissions. The papers are organised according to the following topics: Computational Intelligence, Security, Internet of Things. Papers from the extended track are also presented in the volume.