The treatment and control of coinfections is a key object of global health. As multimorbidity becomes a growing focus in the care of chronic disease in the North and as as new treatments become available and pathogens emerge, coinfections receive increased attention mainly in the South. Not only does this pose a novel challenge to pharmaceutical development and public health, but it also brings up pressing questions about medical care, health policy making and social and individual experiences with infectious and chronic disease. In sum, coinfections and multi-morbidity will pose a challenge not only for practical treatment and care, but also for reflecting on the social and cultural conditions of diseases, their containment and the lives and care trajectories of patients. In 2004, the WHO issued the first comprehensive interim policy on collaborative TB/HIV activities to “assist policy-makers to understand what should be done to decrease the joint burden of tuberculosis and HIV” (2004: 1). This interim policy, actualized in 2012, is the consequence of several years of reports on the specific problems the coinfection of tuberculosis and HIV provided for health officials, treatment campaigns and policy makers. As a matter of fact, disease surveillance, treatment programs, prevention activities and funding streams on tuberculosis and HIV have operated separately ever since HIV/AIDS emerged, reflecting distinct, if not incommensurable disease identities and histories: while tuberculosis has been a curable disease since the 1950s, engendering short-term relations between sometimes highly infectious patients and health professionals, HIV remains incurable and requires long-term care relationships that are regularly accompanied by the formation of self-help groups. Tuberculosis has thus become a neglected disease “without a future” (Kehr 2012) in the North, whereas HIV has ever since the 1980s been a popular focal point for public health actions and funding worldwide. In 2004 a WHO report described the differences between TB and HIV thus: “The different histories and cultures of the TB and HIV communities raise many challenges in achieving an effective and productive partnership.” (Stop TB Partnership, Meeting report, 2004 www.who.int/tb/publications/tbhiv_addis_report/). The symposium’s aim is to raise a set of questions of how to appropriately address coinfections as biosocial phenomena from the perspective of the social sciences and humanities. As a matter of fact, research on coinfections - and on a more general level multi-morbidity - remains a desiderata for social sciences and humanities, despite the fact that their methodology with its focus on patients, care trajectories and health systems could make a very valuable contribution to understanding and tackling this ever more pressing problem. To this end, we will bring together historians, anthropologists and sociologists who have been researching either disease – tuberculosis or HIV/AIDS – with public health professionals that have addressed both diseases in their everyday practice for the last ten years, that is ever since the TB/HIV strategy emerged at the beginning of the new millennium. The symposium will thus not only formulate new research questions and start to develop a methodology to understand coinfections and their control as entangled objects, but also take on the task of forging synergies by bringing together researchers from different disciplines, disease communities and methdologies. The event will thus be the starting point for a long needed methodological and epistemological debate on how to write histories and ethnographies of coinfections and/or multi-morbidity in close dialogue with public health professionals to address practical problems in the field.