Following medical school, Orbinski held a Medical Research Council of Canada fellowship to study pediatric HIV in Sub-Saharan Africa. In 1991, he began working internationally with Médecins Sans Frontières (MSF). After his first mission in Peru, Orbinski served as MSF’s Medical Coordinator in Baidoa during the Somali Civil War and famine of 1992-93, and in Jalalabad, Afghanistan during the winter of 1994. He was subsequently MSF’s Head of Mission in Kigali during the Rwandan genocide of 1994, and in Goma, Zaire during the refugee crisis in 1996-97.