One of the four research institutes comprising the University Health Network, TWRI is home to the research programs associated with the neural and visual sciences, musculoskeletal disease and urban and community health priority programs at UHN. Neuroscientists here explore the function of the nervous system as they develop treatments for spinal cord injuries, cerebral ischemia, vascular malformations, brain tumours, neurophthalmologic disorders and neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease.

TWRI is also home to the Vision Science Research Program, a joint UHN/University of Toronto Program. Their research is directed into the following areas: molecular genetics of blinding eye diseases and brain disorders; treatment, biophysics and psychophysics of glaucoma; eye movement control mechanisms; neuronal damage; retinal degeneration and diabetic retinopathy.

Arthritis and associated degenerative diseases are the focus of the researchers in the musculoskeletal research program. Their investigations are aimed at revealing the causes of, and generating therapies for, these ailments.

TWRI researchers associated with the Healthy Connections program are seeking solutions to public and community health concerns. Toronto Western Hospital serves clients from culturally- and economically-diverse backgrounds. In the research institute they devise and study methods of education, prevention, health promotion and health care delivery in order to better serve this population.