First published as a Special Issue of Interpreting (issue 10:1, 2011) and complemented with two articles published in Interpreting issue 16:1, 2014, this volume provides a comprehensive view of the challenge of identifying and measuring aptitude for interpreting. Following a broad review of the existing literature, the array of eight empirical papers captures the multiple dimensions of aptitude, from personality traits and soft skills such as motivation, anxiety and learning styles to aspects of cognitive performance. The populations studied, with experimental as well as survey research designs, include students and professionals of sign language interpreting as well as spoken-language interpreting, and valuable synergies emerge. While pointing to the need for much further work, the papers brought together in this volume clearly represent the cutting edge of research into aptitude for interpreting, and should prove a milestone on the way toward supplying educators with reliable methods for testing applicants to interpreter training programs.