Invitation The organizing committee of the 5th PSYCO in 2013 extends a cordial invitation to you to come to Caen to meet renowned scholars and practitioners from all over the world. The city of Caen is the capital of Normandy, one of the most attractive European regions due to its historical and cultural richness and natural beauty. Aims Periodic control has been an active research area over the last decades. Several ideas, techniques and approaches have been developed for periodic systems modelling, analysis, identification, prediction, observation and control. The developed theoretical tools have been applied in many industrial fields including aeronautic and aerospace, telecommunications, power systems. This workshop aims at bringing together researchers and practitioners interested in periodic control and its applications in science and engineering. It will provide a forum for presentation of recent developments and assessment of the most promising trends for future research. The scope of the workshop covers all aspects of periodic systems theory e.g. modelling and analysis and periodic signals and dynamics, repetitive control design.