Older adults are the fastest growing segment of the population. With these changing demographics, mental health professionals will be seeing more older clients. Additionally, older adults are an underserved population in that most older adults in need of mental health services do not receive treatment. Thus, it is essential that treatments for mental and behavioral health problems are empirically supported with older adults and that mental health professionals are aware of the special needs of older adult populations. Acceptance and Commitment Therapy (ACT) is an emerging approach to the treatment of distress. The purpose of this article is to provide a rationale for using ACT with older adults based on gerontological theory and research. We also review research on ACT-related processes in later life. We present a case example of an older man with depression and anxiety whom we treated with ACT. Finally, we describe treatment recommendations and important adaptations that need to be considered when using ACT with older adults and discuss important areas for future research. (Contains 1 table.)