Bright light therapy is an accepted and commonly used treatment for seasonal affective and circadian rhythm disorders. In the past 20 years, researchers have examined the effectiveness of bright light therapy in improving depression and agitation in older adults with dementia. This article provides clinicians with a summary of the neurophysiology of bright light therapy, bright light research considerations, an evidence-based bright light protocol, problems related to bright light therapy, and clinical implications for bright light therapy in older adults with dementia. Bright light exposure is a safe, non-pharmacological treatment that is currently underutilised in this population. Clinicians may find bright light therapy beneficial as a primary or adjunctive treatment in reducing depression and agitation in older adults with dementia.