The Oxford University Clinical Research Unit (OUCRU) is a large-scale clinical and public health research unit with site offices in Viet Nam, Indonesia, and Nepal. Part of the Centre for Tropical Medicine and Global Health at the University of Oxford (UK), OUCRU was first established in Ho Chi Minh City in 1991, hosted by the Hospital for Tropical Diseases (HTD), Viet Nam. In 2003, OUCRU-NP was established in Kathmandu, Nepal, hosted by Patan Hospital and the Patan Academy of Health Sciences. OUCRU Hanoi was established in 2006 in partnership with the National Hospital of Tropical Diseases (NHTD), Viet Nam. In 2008, the Eijkman-Oxford Clinical Research Unit (EOCRU) was established in Jakarta, Indonesia, in partnership with the Eijkman Institute for Molecular Biology and Faculty of Medicine University of Indonesia. Our vision is to have a local, regional and global impact on health by leading a locally-driven research programme on infectious diseases in Southeast Asia. Our research programme covers clinical and laboratory research with hospital and community-based patient populations, including epidemiology, immunology, host and pathogen genetics, molecular biology, microbiology and virology, mathematical modelling, bioinformatics, biostatistics, and social science. This work is supported by an extensive clinical trials unit and data management centre compliant with national and international regulations and comprehensive management, finance, public engagement, and administrative support offices. OUCRU receives considerable support from Wellcome Trust as part of the Africa and Asia Programmes. Together with our partners, we have led a highly successful effort in enhancing the infrastructure and capacity to perform clinical trials and basic scientific research in Viet Nam, Indonesia, and Nepal.