Although interdisciplinary research is becoming the dominant model for understanding complex health issues, little is known about the competencies required for successful interdisciplinary collaboration. Published research has discussed attitudes about interdisciplinary work and organizational resources but not the needed competencies. This report describes the method and results of the competency specification process for health research. Based on an established definition of interdisciplinary research, a preliminary set of competencies was developed from expert opinion of key informants and a review of the interdisciplinary research literature. A Delphi panel of interdisciplinary researchers then reached consensus on 17 competencies necessary for interdisciplinary research.