TarChoon Aw trained in internal medicine at the Singapore General Hospital. He has specialist certifications in Internal Medicine from the National University of Singapore (NUS) and the Royal College of Physicians, UK. He underwent further training in laboratory medicine at the Hospital of the University of Pennsylvania, Philadelphia, USA. He has specialist certification in Pathology from the Royal College of Pathologists of Australasia. Currently, he is Director (Chemical Pathology) in the Department of Laboratory Medicine at Changi General Hospital. Since 2014 he has been Clinical Senior Lecturer (Medicine) at NUS School of Medicine. Since 2020 he is Clinical Professor (Pathology) at the Duke-NUS Graduate School of Medicine. He is also Attending Physician at Raffles Hospital. At the NUS Medical School from 1980 to 2006, he attained the rank of full Professor (Pathology) and served as its Vice-Dean (1994–2002). He was Chief (Laboratory Medicine) at the National University Hospital from 1988 to 2002 and Medical Director of the Alexandra Hospital (1995–2000). From 2006 to 2010 he was part-time staff at Monash Medical School as Professor (Chemical Pathology, Malaysia campus) and Honorary Professor (Medicine, Australia campus). He is on the editorial boards of several journals including Annals of Thyroid Research, Malaysian Journal of Medical Science, Indonesian Biochemistry Journal, Proceedings of Singapore Healthcare, Scientific Reports and Diagnostics.