The Disease Reference Group on Chagas Disease, Human African Trypanosomiasis and Leishmaniasis (DRG3) was part of an independent thinktank of international experts established by the Special Programme for Research and Training in Tropical Diseases (TDR) to identify key research priorities through systematic review of research evidence and input from stakeholders. These three distinct insect-borne diseases, while caused by related kinetoplastid protozoan pathogens, have dissimilar geographical distributions a reflection of their different insect vectors and range of vector contact with humans. The diseases disproportionately afflict poor and remote populations with limited access to health services; the pathogenic mechanisms are poorly understood but typically entail immunological processes