This book is intended to discuss important issues concerning Requirements Engineering (RE) and Human-Computer Interaction (HCI), especially the ones related to usability and accessibility. It is dedicated to observations, concepts, approaches, frameworks and practices that promote understanding, facilitating, and increasing the awareness of the role of usability and accessibility requirements and their proper integration into the requirement engineering process. The book is based on the two workshops on Usability- and Accessibility-focused Requirements Engineering (UsARE), which took place in 2012 and 2014. The first event, UsARE 2012 [8], was supported by IEEE and was held on June 04, 2012 in conjunction with the IEEE 34th International Conference on Software Engineering (ICSE 2012) in Zurich, Switzerland. The second event, UsARE 2014 [9], was supported by IEEE and IFIP and was held on August 25, 2014 in conjunction with the 22nd IEEE International Requirements Engineering Conference (RE 2014) in Karlskrona, Sweden. On both occasions, each submission was reviewed by at least three program committee members. This was followed by discussions amongst the organizers which led to a total number of 7 accepted papers for UsARE 2012 and 8 accepted papers for UsARE 2014. On both occasions, the workshop proceedings were published online by the IEEE Xplore Digital Library. The workshop summary and the results of the interactive session of the first event were published as a report in the ACM Software Engineering Notes in the issue of January 2013 [2].