Dennis Choi received the MD degree from the Harvard-MIT Health Sciences & Technology Program, as well as a PhD degree in Pharmacology and neurology residency/fellowship training from Harvard, before joining the faculty at Stanford in 1983. In 1991, he went to St. Louis to be the Jones Professor and Head of Neurology at Washington University, Neurologist-in-Chief at Barnes-Jewish Hospital, and Director of the McDonnell Center for Cellular and Molecular Neurobiology and the Center for the Study of Nervous System Injury. At the end of 2001 he joined Merck Research Labs as Executive Vice-President for Neuroscience, leaving in 2006 to accept appointments at Boston University as Professor of Pharmacology and Experimental Therapeutics.

In 2007 he joined Emory University as Executive Director of the institution's Neurosciences Initiative. He is currently a member of the Institute of Medicine and its Board on Health Sciences Policy as well as Neuroscience Forum; the Executive Committee of the Dana Alliance for Brain Research; the Government and Public Affairs Committee of the Society for Neuroscience, and the Visiting Committee advising the Harvard-MIT Health Science and Technology Program. He is a fellow of the American Association for the Advancement of Science (AAAS). Past service has included the National Academy of Science's Board on Life Sciences, multiple editorial boards (including the Board of Reviewing Editors for Science, and founding co-editorship of Neurobiology of Disease) and advisory boards, presidency of the Society for Neuroscience, chairmanship of the US National Committee to the International Brain Research Organization, and vice-presidency of the American Neurological Association.

He is currently appointed a Visiting Professor in Clinical Neuroscience at Oxford University in England, and Visiting Distinguished Professor at KAIST in Korea. His research on mechanisms of brain or spinal cord injury has been recognized by several awards, including the Silvio O. Conte Decade of the Brain Award, the Wakeman Award for Neurosciences Research, the Christopher Reeve Research Medal, and the Ho-Am Prize in Medical Science.