Effective career guidance systems provide students with the opportunity to gain first hand experiences of what it is like to be in work. Students in general secondary education in many countries are encouraged and enabled by their schools to participate in short duration internships (also known in some countries as work experience placements). Undertaking tasks under the supervision of a working professional who is not a teacher in an authentic workplace provides students with considerable opportunities for career development. This policy brief reviews data on the impact of such internships on the employment outcomes of young people. It also explores why positive benefits might be expected when provision is of good quality in light of theories of human, social and cultural capital and wider research on the opportunities for learning presented by workplace exposure. Finally, it summarises findings from research literature on how schools can optimise positive outcomes for students, and draws on the OECD PISA study to present data on patterns of student participation.