Before entering a career in regional and national politics, Sánchez worked as a parliamentary assistant in the European Parliament, and as chief of staff to the United Nations high representative in Bosnia during the Kosovo War; he was also a Professor of Economics, publishing a version of his doctoral thesis “La nueva diplomacia económica europea”.
Sebelum memasuki karier di politik regional dan nasional, Sánchez bekerja sebagai asisten parlemen di Parlemen Eropa, dan sebagai kepala staf perwakilan tinggi PBB di Bosnia selama Perang Kosovo; ia juga seorang profesor ekonomi, menerbitkan versi tesis doktoralnya “La nueva diplomacia económica europea”.