Fundamental and practical challenges facing our society can be addressed with new methods and thus approached from a new perspective. Examples of present day challenges are energy conversion, information technology, new materials and biology and medicine.Over the last decade, ultrafast science and technology have made enormous progress, opening a large variety of new research fields and applications. Examples include table-top high-harmonic generation that allow new forms of spectroscopy and diffraction, lab-based sources of ultrashort electron pulses and sources of terahertz radiation that opened new directions in materials science, chemistry and biology and new sources of ultrashort X-ray pulses, such as X-ray free electron lasers.The Lausanne Centre for Ultrafast Science (LACUS) brings together the EPFL teams working in Ultrafast Science and Technology with experimental and theoretical methods as well as those using ultrafast technology in different applications. Research areas are very diverse, spanning from fundamental to applied research and they present a very high degree of complementarity. Several EPFL groups are pioneers in ultrafast science and technology and LACUS pools in the expertise in the development and the use of advanced ultrafast laser technology, X-ray and electron technology and associated methods, along with the EPFL theory groups. It also aims at complementing and strengthening existing Swiss scientific infrastructures, e.g. the Swiss Light Source and the SwissFEL.