This special issue is composed of a collection of selected papers presented at the Fifth International Symposium on Intelligent Systems Technologies and Applications (ISTA'19) that was organized in association with Springer, Germany and IOS-Press, Netherlands. ISTA'19 was co-affiliated with the International Conference on Applied Soft computing and Communication Networks (ACN'19), held in Trivandrum, Kerala, India during December 18-21, 2019. The Symposium brought together researchers in related fields and provided a venue to explore and discuss various aspects and recent advances in the area of intelligent systems technologies and applications. It offered an excellent opportunity for the presentation and discussion of interesting new research results, which contributed to effective dissemination and transfer of knowledge. Included in this special issues are 50 selected papers covering topics pertaining to the application of soft computing and computational intelligence techniques to a wide spectrum of issues in the areas of image processing and computer vision, natural language processing, pattern recognition, biometric identification, security systems and data encryption, cloud computing, control systems, and network design.