People are living longer, and in better health, than in any prior point in history, with far-reaching but as yet underrecognized implications for mental health professionals. This phenomenon affects both the developed and the developing world. With greater numbers of older people, mental health professionals will need to develop greater awareness, understanding, and appreciation of gerontology to deliver optimally effective psychotherapy with this population. The nature of psychological issues encountered in clinical practice will also change—for example, intergenerational issues among blended families, increased retirement and leisure time, and expectations of greater health and productivity in later life from baby boomer cohorts. These issues are important for mental health professionals to recognize, as the increased sophistication of the baby boomer generation in terms of health care will lead to higher expectations of mental health care. The authors have chosen to discuss the implications of an ageing population with reference to a cognitive– behavioral perspective, but the issues raised here and practical suggestions contained within this article are not restricted to practitioners of Cognitive–Behavior Therapy.